after few days ago when I was offered v13 update, today I can no longer create fluid gif recordings. it records first few seconds then it misses movement for several seconds.
win 1903, hd graphics 530, driver version 22.20.16.4836
incoming video demonstration (filmed with phone)
you can observe how the sequence when browser is opening the page is missed (connection progress details in the status bar)
gif: https://drive.google.com/file/d/1WvKAIkOxLY6UOqxIgCndXVnfAWj7Cpjw/view?usp=sharing-NOCRAWL
filmed with phone: https://drive.google.com/file/d/1FVjxuDH-L1fGGiewRGkxbGhoQ5errv1U/view?usp=sharing-NOCRAWL
remove -NOCRAWL appended to prevent scavenging bots
if you read these by mail, please view updated upload links on github, first ones were wrong
Not sure if every, but most recorded gifs look like it suddenly freezes after few seconds from start. At some point frames start missing.
Example where mouse pointer stops moving although it is moved during all animation:

Try updating FFmpeg to see if that resolves the issue:
From ShareX
Task settings... > Screen recorder > Screen recording options… > Download
@robertgz Thanks! Updating FFmpeg solved the issue in my case.
I had the same problem, and updating FFmpeg resolved it for me too.
The instructions above were a bit confusing to me since I wasn't familiar with where to go to configure FFmpeg. Now that I've fixed GIF recording, I can demonstrate or anyone else thick-headed like me 😄
In ShareX 13.0.1, I found it under Task Settings -> Capture -> Screen Recorder -> Screen recording settings... then click "Download" at the top.

Most helpful comment
Try updating FFmpeg to see if that resolves the issue:
From ShareX
Task settings... > Screen recorder > Screen recording options… > Download