I have one tbh that seems to be having the same problem.
made efforts to fix it twice, both times afterward, they refuse to follow the fix.
Going for strike three here and if they don't take to that, well, I'll give them a shot in a different hive
I use top bars with a 1 inch wide wood strip ( like a paint stick) attached to the bottom now, the first bars in this particular hive had the wax string, which they ignored completely.
to be honest, I think they were given too much room to start with in this hive, normally, I find that starting them with only like 5 or maybe 7 top bars keeps them close enough, but there were troubles a helper was having when starting this one. Hey, it happens. Chalk it up to a learning experience, is what I say.