Currently I only tested 2 mods (Forbidden and Arcanus and Supplementaries) but the frames (the black outline of the block when the player looks at it) are invisible/see-through.

Interesting I will need to investigate

I just saw that there are 2 alpha versions above the one I am playing, I will test and see if it happens on those (I was in 1.0.50-ALPHA)

Is it just with modded blocks?

It still happens with vanilla oak planks (oak , dark oak, spruce and not only the doors)(domum_ornamentum-1.18.2-1.0.55-ALPHA-universal.jar)

(the missing texture is when I tried some of the planks from Chipped)

Not reproduceable.
Is it still an issue?

Yes its still there.
(Also the arcane crystal blocks seem to be transparent now, I don't know if that is intentional.)

Is it just with modded blocks?

The timberframes afaik are on purpose just 99% of blocks size, to make sure that the block behind them renders, shadows work properly etc

I am also having this issue at this time. Its only ever the block your aiming at but it results in the build looking funky.