AppOfflineError: Connection to server failed (1006) Errors

What I’m trying to do:
My app has gotten a number of users and I am encountering a number of errors. I am working with Jay and Stu on them and sent an email to Anvil support, where Ryan asked me to post about them in the forums. We have checked each of these extensively and couldnt solve them, so would love support!

Here I have many situations where I get an app offline error, dated after the outings we had last week.

There are 2 errors, actually:
anvil.server.AppOfflineError: Connection to server failed (1006)
anvil.server.AppOfflineError: Connection to server failed (error)

Session IDs:
HFSFF7KRLAJW6XUXRKOTWXGYBFO7VBZR - Tue 16.4 around 11:00 CEST
TPPXIT3GXHR5V2UHJP5FMX3MUZLNQRHE - Sun 14.4 around 21:30 CEST
OWVZM5GTRSR7KBSKIPVIA5SEUEFMEHEI - Mon 8.4 around 21:42 CEST
NDGDMN4OCO4FWWVAZUN7AXEWGIA7SY5H - 3.4 around 9:00 CEST

The server code that was being called in the top session:

@anvil.server.callable
def handle_ai_still_generating(session_id):
    session_row = app_tables.session_info.get_by_id(session_id)
    show_generation_limit_reached_msg = session_row['show_generation_limit_reached_msg']
    if show_generation_limit_reached_msg == True:
        #reset it directly, because we're about to use it to show the message and dont want to show the message again
        session_row['show_generation_limit_reached_msg'] = False
    ai_generating = session_row['ai_generating']
    if ai_generating == False:
        #reset it directly, because we're about to use it to show a success message and dont want to show the message again
        session_row['ai_generating'] = None
    return ai_generating, get_num_learning_cards(session_id), show_generation_limit_reached_msg