Your wireless may be dropping because there are two wireless access points with the same name and password. This is typical when you have a 2.4 gHz segment and a 5 gHz segment of the same router. Your wireless may be roaming, looking for a better connection. If this is the case, I suggest that you rename the access points; something like myrouter2.4 and myrouter5.
Your wireless may be dropping because of power management; that is, the feature where the card partially powers down to save battery power during periods of inactivity and then, ideally, powers back up seamlessly when activity resumes. Let's disable power saving to see if it helps. From the terminal:
sudo sed -i 's/3/2/' /etc/NetworkManager/conf.d/*
Your wireless may be dropping because the channel to which it was connected has suddenly changed. Please be certain to set a fixed channel, not auto-select.
After making these changes, reboot the router.
EDIT1: In both pastes, we see many repeats of the following:
ieee80211 phy0: Hardware restart was requested
iwlwifi 0000:04:00.0: Queue 2 is stuck 0 2
iwlwifi 0000:04:00.0: Microcode SW error detected. Restarting 0x0.
iwlwifi 0000:04:00.0: Start IWL Error Log Dump:
In other words, as soon as the wireless device/driver/firmware combination sees and tries to connect with an access point; usually your own router, it stumbles on a stuck queue, dumps the firmware and restarts. All of this takes some seconds of time, during which you are disconnected and then reconnected.
In the Starbucks case, your wireless recovers and then connects to, I assume, the relatively simple 2.4 gHz router and doesn’t stumble.
In the case of your home router, I’m confident that the advanced Intel AX200 tries to connect to the 5 gHz segment and stumbles, disconnects, recovers, etc. again and again.
I suggest that we try some driver parameters to see if we can fix it. Please open a terminal and do:
sudo -i
echo “options iwlwifi amsdu_size=1 disable_11ax=true” >> /etc/modprobe.d/iwlwifi.conf
echo “options iwlmvm power_scheme=1” > /etc/modprobe.d/iwlmvm.conf
exit
We are disabling 80211ax even though your device is capable, because neither your router nor Starbucks are capable.
Reboot and tell us if there is any improvement:
sudo dmesg | grep iwl
I also suggest that you bind to the 5 gHz segment of your router like this: 19.10 Ubuntu automatically connects to a weaker Wi-Fi Please note that the 2.4 and 5 gHz segments will have different MAC addresses; you want to bind, of course to the 5 gHz segment.