Sadly most IPB owners, and I include my past self, are brainwashed into getting the upgrades and the attendant headaches setting everything up.
IF IT AIN'T BROKE....
The last forum was fine, as was the one before that. This one has teething issues which will be ironed out and then a new update will arrive.
So many plugins ..so much temptation to stuff your pockets with sweets...in the case of IPB.... bloatware
THE LAST FORUM WAS FINE but people are obsessed with the idea that last versions must be problematic version..all new versions must add value or so we are brainwashed into thinking.
Get this new board fixed and then leave it as is unless there is a function that needs an update or a new plugin that is a must have come along.