Professor Onyx bug
While I was playing MTGA I used Professor Onyx's +1 ability, the Liliana planeswalker from the strixhaven set, and was able to look at the top 3 cards of my library. Once I was able to see that I could choose between several cards, including one that would allow me to 'learn', I checked my sideboard to see what spells might interest me to take the 'learn' card. Once I made my decision, the game would not let me select my card. None of the 3 choices of Liliana's ability were able to be selected. I assume that this is a bug on the client's end because the internet connection was not severed...the opponent was still able to send emotes to me while I was struggling to select a card from Liliana's ability. I ended up losing the ranked match because I could not select an option in time. I am playing on a Windows Surface laptop, in case that helps resolve the bug.
This was super frustrating and it cost me a game that I was likely to win in a ranked standard match.