I accidentally press the Function key all the time, which opens up the emoji picker. When I do that, the cursor freezes in the last position I had it at.
When you take a screenshot with Command + Shift + 4, it does the same thing, however, Command + Shift + 3 works just fine.
Press Command + Tab or Tab Switcher, then go back to the Roblox Client, move your cursor where you want it to go, then if you want to move it again, repeat the process.
Eventually doing this a couple of times will result in normal behavior with the cursor.
If you want to take a free form screenshot, use QuickTime Player.
CPU/GPU: Apple M1
Ram: 8 GB
Storage: 512 GB SSD
OS: macOS 11.4
Model: MacBook Air M1
You should be able to open the emoji picker and take a screenshot with Command + Shift + 4 with no problems.