I am not sure if this is related, but I had a weird portrait bug with Minsc once that was caused by him having the Titanstring Bow equipped when leveling up/ reskilling.
That's exactly what I was talking about re Minsc's portrait. For me it usually happens with the Dead Shot, but I guess any bow/longbow can trigger this? Or at least that model of longbow as I think Titanstring and Dead Shot use the same basic model.
His portrait will show the correct pose and all that but will be super dark with a bit of bow-string superimposed over it. Quite easy to ID that superimposed object when it's happening with the Dead Shot as that bow's string is bright pink or red.
This has happened pretty much from the start for me - possibly even during my first run which must've been in late 2023.
I've still seen it happen on patch 7, when I forget to use my workaround. Which is to not equip any non-default items on Minsc when I first pick him up and then level him from 1 to 12. Seems to do the trick as it's been a long time since I've seen that particular glitch.
