I noticed it first during Direnni Tower while tracking a temple quest target (first dungeon I did tonight and yeah, I grabbed a quest from the Temple in one of Balfiera's cities while I was waiting for the time to pass for Medora's quest and the quest took me to Direnni Tower as destination too) and now I'm at Lysandus Tomb and I'm having the same issue again.
Thing is, is not constant and doesn't always happens... both times, first at Direnni and now in this dungeon, I wasn't having a problem and everything was normal... but after some time roaming around, I started having the issues... what I notice is that I can't hit enemies at all, or at most 1 hit every 10 to 20 swings, and I have to resort to use magic to kill them. That happens with both weapon types, I even tried with Hand to Hand and the same happens, but my H2H skill is rubbish, so I can't take that test into account.
Not sure if it's the geometry of some areas interfering, or what else... I'll attach a have where I'm standing in front of a Vampire swinging like a mad man and I'm not able to get a hit at all. Is there any way to see hit rolls or modifiers in game?
Last time it happened I restarted the game and that seemed to solve the issue for a while, perhaps it's something that's happening after a long while of the game running? So it may be the case that when testing for anyone that loads the save needs a while to get the issue again, that would make it difficult to track and reproduce :/
As for mods, I'm using a lot of them (is there a way to generate a list from inside the game?), I've attached the Mods.json file that contains the list of mods that the game sees... I think. Also, I upgraded most mods that I could to their latest versions, unless I missed some... but I'd guess is something borked on my character rather than a mod's doing, but I can't be sure :/
I recorded a short video of the issue showing while I was fighting a Vampire (a different one than the one in the Save I attached...) and a second short video because I forgot to show the combat stats in the first one
Spoiler!
EDIT: typo
EDIT2: edited title to signal that the issue is solved for me!