Thanks for reaching out; this shouldn't be happening!
Please let us know which browser are you working on? What type of project are you facing this issue with? Is it a specific project or a specific kind of project (web, video, or post)? Do you get any error messages when you try to convert them? Have you tried clearing the cache/cookies of the browser to check if that makes any difference?
I'd also suggest you go through these articles and see if the mentioned steps help you resolve this: