I have had a similar issue to this today.

Whilst doing a MTG Arena Vintage Cube draft near the start of pack 2 (I cannot remember the exact pick) the game auto selected the last card in the pack and would not allow me to select any other card. I attempted to drag other cards into my deck and double click them like normal none of which worked and then it auto selected the last card when the timer ran out. Tabbing out and in, minimising and unminimising the window did not fix this problem. It occured for the next pick as well at which point I had to restart my game meaning I'd lost at least 3 picks of selection.

At the end of the draft my game also experienced a network error meaning I missed the final three picks.

All of this put together meant I missed 6 of the 45 picks in the draft which obviously had a big impact on my ability to draft effectively. As a ftp player this is also very consequential as it means I lose out on rewards I am using to continue being able to play.

The log is from immediately after the draft finished.