Problems uploading .fit file using Firefox or Safari

Normally I use my Mac with Safari BUT a few minutes ago I used my other PC (Win11 with Edge) and the Upload of the FIT files worked without any issue.

the Upload in FIT File Viewer worked fine.
I am using Mac witht Firefox. I tried Safar which didn't work either.

So I installed Google Chrome and tried again, that worked.

I hope Garmin is fixing this soon, would be a shame if Upload only works with Chromium based Browsers.

Thank you for your fast reaction and help!

thanks for you answer, I tried Chrome on Mac and that worked also, so it seems a Chromium based Browser like Chrome or Edge is the solution

Thanks for the update. Meanwhile I've contacted Garmin Support to open a ticket. Also joined this thread to the main thread on this topic.

I ran into the same issue today. Getting the error message on Edge, but when using Chrome it seels to load at first, but then there seems to be a grey loading bar that just stays there and nothing happens. The activities are not added

forums.garmin.com/.../problems-uploading-fit-file-using-firefox-or-safari

Same for me - shows like this on both Edge and Chrome, even with original Garmin files. Have you found a solution yet?

Well, it might be an iPad problem because I can’t upload on chrome, DuckDuckGo, or safari 

same issue for me for the last week, upload errors using Firefox, fine using Chrome. Clearing the cache and cookies in Firefox didn't help. Come on Garmin, get it sorted.