I just happened to be doing some work in TT just now, adjusting our next three weekly meetings to be Virtual and noticed that a Money Account was created for each of the meetings I edited. I also created a new Event and it did default to the Generic Events money account we have saved. I think the issue is events that were created prior to whatever updates were made. I looked at a future meeting and it shows Create a New Money Account. We created our Recurring weekly meeting the beginning of the year before the updates to Money Accounts and Default accounts. I created a new Recurring meeting and it did have the Generic Events money account associated with it.
For a work around now just try to remember when you are going into an old event to edit select the Advanced tab and change the Money Account to whatever your Generic Default is.
There could also be differences in how things work based on your settings, we are not currently using the Dynamic Meeting Invitations, not sure if that makes a difference.