Yeah, that happened to me to. I wanted to insert a game, but it was too big, and I couldn't change they type of pieces. I was using Ocean, and I wanted to change it to Gothic. It was too big, and I couldn't see the Settings button.
About inserting diagrams for puzzles and games...
I noticed that on my phone with inserting an image but I could scroll around the dialog to get it working.
and for the inserting pictures thing:
except you could actually scroll on the inserting images function though not inserting the board
I use Brave, Chromium 81


For some reason today I was inserting a game and the “set up board, “load pgn, and the other things were big and I couldn’t see the whole board. It made it very hard to put my analysis in it since I couldn’t move the board so I could see it all. Yesterday it was normal, but today it went super big and I couldn’t see every single part like I usually do. Please try to fix this bug thanks