Similar story for me, but switching from Proton 9 to Proton 10.0-4 in Steam was enough to fix it for me.

i lost in draft because of not being able to mulligan, i hope there is some compensation about it

Using Proton 11.0-2 fixe the issue for me.
I forgot to say i'm using steam on Linux Mint.

Got a solution that worked for me! Same issue. I'm on Linux Mint, running Arena with GE Proton, and updating the version fixed the issue.

GE-Proton9-27 did NOT work
GE-Proton10-34 works

Hope that helps! I know there are more recent versions of GE Proton, which I have not tested. If you're not familiar with GE Proton, there's tutorials on YouTube to install. It sometimes works better than Steam's Proton for compatibility issues.

I have exactly the same problem since the last update. I tried to restart, repair game files, disable/enable steam overlay etc. no change of dragging and dropping :(

Can't scry or surveil, the cards can't be dragged, occurs across all games and regardless of restart. I've had to repeatedly forfeit games because of this.

Confirming that scrying is also affected and that the bug still exists.

Same/similar problem. Unable to drag/drop cards in deckbuilding or in-game. Log included.

Same/similar problem. Unable to drag/drop cards in deckbuilding or in-game. Log included.

Same/similar problem. Unable to drag/drop cards in deckbuilding or in-game. Log included.

Same/similar problem. Unable to drag/drop cards in deckbuilding or in-game. Log included.

It seems to be a problem with the mouse tracking. The movement feels sluggish when I’m playing.

Same.
Also affects drag and drop for ordering damage or effects

Same here, after yesterdays update on Steam can't scry / surveil or mulligan without losing cards plus searching is only possible with a mousewheel. Had to drop off from an event because i couldn't mulligan. Are there any compensations for this issue regarding wasted resources?

Same since the last update made yesterday.

Same since the last update made yesterday.
And I can't use the scroll bar to browse through the cards.