Failed to fetch..Hash Sum mismatch and Some index files failed to download, error

I'm taring to run those commend on the terminal

sudo add-apt-repository ppa:oibaf/graphics-drivers
sudo apt update
sudo apt upgrade

and those error show up

E: Failed to fetch
 http://il.archive.ubuntu.com/ubuntu/dists/focal-updates/universe/cnf/Commands-amd64.xz  Hash Sum mismatch

...

E: Some index files failed to download. 
They have been ignored, or old ones used instead.

I tried those commend to solve the problem but noting work

sudo apt-get clean

sudo rm -r /var/lib/apt/lists/*

Full output of sudo apt update

Hit:1 http://il.archive.ubuntu.com/ubuntu focal InRelease
Get:2 http://il.archive.ubuntu.com/ubuntu focal-updates InRelease [114 kB]     
Hit:3 http://il.archive.ubuntu.com/ubuntu focal-backports InRelease            
Hit:4 http://ppa.launchpad.net/oibaf/graphics-drivers/ubuntu focal InRelease   
Get:5 http://il.archive.ubuntu.com/ubuntu focal-updates/main i386 Packages [490 kB]
Get:6 http://il.archive.ubuntu.com/ubuntu focal-updates/main amd64 Packages [1,032 kB]
Get:7 http://il.archive.ubuntu.com/ubuntu focal-updates/main Translation-en [230 kB]
Get:8 http://il.archive.ubuntu.com/ubuntu focal-updates/main amd64 DEP-11 Metadata [283 kB]
Get:9 http://il.archive.ubuntu.com/ubuntu focal-updates/main DEP-11 48x48 Icons [60.5 kB]
Get:10 http://il.archive.ubuntu.com/ubuntu focal-updates/main DEP-11 64x64 Icons [95.1 kB]
Get:11 http://il.archive.ubuntu.com/ubuntu focal-updates/main DEP-11 64x64@2 Icons [29 B]
Hit:12 http://archive.canonical.com/ubuntu focal InRelease                     
Get:13 http://il.archive.ubuntu.com/ubuntu focal-updates i386 Contents (deb) [22.1 MB]
Hit:14 http://security.ubuntu.com/ubuntu focal-security InRelease         
Get:15 http://il.archive.ubuntu.com/ubuntu focal-updates amd64 Contents (deb) [47.4 MB]
Get:16 http://il.archive.ubuntu.com/ubuntu focal-updates/main amd64 c-n-f Metadata [13.5 kB]
Get:17 http://il.archive.ubuntu.com/ubuntu focal-updates/restricted i386 Packages [17.7 kB]
Get:18 http://il.archive.ubuntu.com/ubuntu focal-updates/restricted amd64 Packages [272 kB]
Get:19 http://il.archive.ubuntu.com/ubuntu focal-updates/restricted Translation-en [39.5 kB]
Get:20 http://il.archive.ubuntu.com/ubuntu focal-updates/restricted amd64 c-n-f Metadata [456 B]
Get:21 http://il.archive.ubuntu.com/ubuntu focal-updates/universe i386 Packages [577 kB]
Get:22 http://il.archive.ubuntu.com/ubuntu focal-updates/universe amd64 Packages [784 kB]
Get:23 http://il.archive.ubuntu.com/ubuntu focal-updates/universe Translation-en [171 kB]
Get:24 http://il.archive.ubuntu.com/ubuntu focal-updates/universe amd64 DEP-11 Metadata [330 kB]
Get:25 http://il.archive.ubuntu.com/ubuntu focal-updates/universe DEP-11 48x48 Icons [205 kB]
Get:26 http://il.archive.ubuntu.com/ubuntu focal-updates/universe DEP-11 64x64 Icons [364 kB]
Get:27 http://il.archive.ubuntu.com/ubuntu focal-updates/universe DEP-11 64x64@2 Icons [29 B]
Get:28 http://il.archive.ubuntu.com/ubuntu focal-updates/universe amd64 c-n-f Metadata [17.7 kB]
Get:28 http://il.archive.ubuntu.com/ubuntu focal-updates/universe amd64 c-n-f Metadata [17.7 kB]
Get:28 http://il.archive.ubuntu.com/ubuntu focal-updates/universe amd64 c-n-f Metadata [17.7 kB]
Get:28 http://il.archive.ubuntu.com/ubuntu focal-updates/universe amd64 c-n-f Metadata [17.7 kB]
Get:28 http://il.archive.ubuntu.com/ubuntu focal-updates/universe amd64 c-n-f Metadata [17.7 kB]
Get:28 http://il.archive.ubuntu.com/ubuntu focal-updates/universe amd64 c-n-f Metadata [17.7 kB]
Get:28 http://il.archive.ubuntu.com/ubuntu focal-updates/universe amd64 c-n-f Metadata [17.7 kB]
Get:28 http://il.archive.ubuntu.com/ubuntu focal-updates/universe amd64 c-n-f Metadata [17.7 kB]
Ign:28 http://il.archive.ubuntu.com/ubuntu focal-updates/universe amd64 c-n-f Metadata
Get:28 http://il.archive.ubuntu.com/ubuntu focal-updates/universe amd64 c-n-f Metadata [17.7 kB]
Err:28 http://il.archive.ubuntu.com/ubuntu focal-updates/universe amd64 c-n-f Metadata
  Hash Sum mismatch
  Hashes of expected file:
   - Filesize:17744 [weak]
   - SHA256:b276cfadcfca9a55e5c550b363ff1ad159740034bc0cd3217abf22812039533e
   - SHA1:170f2bcf508eeba44bfdf53acb57621481fde361 [weak]
   - MD5Sum:48a3434d3aaa43754acfe947b8ad35be [weak]
  Hashes of received file:
   - SHA256:7ca4637ad5e301229b9d8e8a1ef912f152cd94b034ba3bd37b758d1144fdf343
   - SHA1:6d39c519e577c936c370d9ea0f5bd99476273897 [weak]
   - MD5Sum:9d022b5ab971ce3553c520acf579eb5b [weak]
   - Filesize:17744 [weak]
  Last modification reported: Wed, 16 Jun 2021 18:18:29 +0000
  Release file created at: Thu, 17 Jun 2021 14:13:58 +0000
Fetched 132 kB in 4s (34.8 kB/s)                                            
Reading package lists... Done
E: Failed to fetch http://il.archive.ubuntu.com/ubuntu/dists/focal-updates/universe/cnf/Commands-amd64.xz  Hash Sum mismatch
   Hashes of expected file:
    - Filesize:17744 [weak]
    - SHA256:b276cfadcfca9a55e5c550b363ff1ad159740034bc0cd3217abf22812039533e
    - SHA1:170f2bcf508eeba44bfdf53acb57621481fde361 [weak]
    - MD5Sum:48a3434d3aaa43754acfe947b8ad35be [weak]
   Hashes of received file:
    - SHA256:7ca4637ad5e301229b9d8e8a1ef912f152cd94b034ba3bd37b758d1144fdf343
    - SHA1:6d39c519e577c936c370d9ea0f5bd99476273897 [weak]
    - MD5Sum:9d022b5ab971ce3553c520acf579eb5b [weak]
    - Filesize:17744 [weak]
   Last modification reported: Wed, 16 Jun 2021 18:18:29 +0000
   Release file created at: Thu, 17 Jun 2021 14:13:58 +0000
E: Some index files failed to download. They have been ignored, or old ones used instead.

How do I solve this problem? Thanks!

It doesn't appear to be the fault of the new ppa you added: rather, it seems to be an error in the ubuntu archive you are using. I wasn't able to reproduce it: can you try again? It's possible you were working while the archive was in the middle of updating itself.