WiFi in the picture (especially for the Library PC. Use a Wired connection if possible) can make things more difficult.
WiFi band connection shifts (1 is an 5GHz the other 2.5GHz)
Windows Updates in the background (Mine typically show up on Tuesdays)
Your ISP
supplied router got an update (I used to log into it and make the desired settings...now I have to use an app on my phone
)
Your Security suite (if not defender) got updated (1 or more times a day.. depending on plan)
FWIW Local works for me just fine (not using httpS) W10 Calibre 7.7