you can't expect ,tracks from long ago patches to all keep right on working in a Modded game
I don't expect it to happen
and of coarse the all work in "a default (stock) game" like 4.10
after all,they were all made on a default Stock game
A lot has changed,why so many people expect every single thing ,
from any default part of the game to remain compatible is beyond me
We are modding the game,changing the game
is the way I look at it
Most old tracks ,are what
a bunch of videos of things people have done ete ete
and...Nothing most of us have not already watched numerous times in the past 10 years
Make some new tracks

sorry just have to laugh,this is just all IMHO
other than that,I don't know if it will be fix,or if it is even getting looked into or not
You can always just switch UP 3 off,
and start the default Stock game,
and watch all your old tracks

I'm trying to say, tracks recorded over the different stock patches (407, 408 409 etc) and mod packs AAA1.2 and UP1.8 and UP2 just don't replay as they should on UP3 but they work fine on stock 4.10.1