Hello ^^ I’m having the same problem with unity trails; as a temporary solution I would advise you to take a look at Melee Weapon Trail package in the asset store which is free. Melee Weapon Trail | Particles/Effects | Unity Asset Store
It fixed my problem and I hope it fixes yours as well.
Also here is a very long discussion about sword trails in unity; I’m pretty sure there is some knowledge in there that might help you.
[SOLVED] Unity Trail Renderer Issue. :( - #14 by veer
Since I am pretty confused about trails myself at the moment, please do let me know if you find out any new information. And since you said it might be about the version, can you point me towards any other guides that use the vfx graph and fixed this problem even though its in another version; because its no problem for me to change versions ^^
Hope this is useful <3