I will report your problem to the technical department. Usually this problem is caused by too much browser cache. You can try changing a browser or clearing the cache of the current browser.
Oh, haven’t thought of changing browser. A follow-up to this:
Tested with Edge, I was able to upload a few tracks before getting the HTTP error again.
I’ll test it out with Chrome, thanks for the temporal quick fix!
I have discussed this issue with the technical department, and the cause is still unclear. Network instability or other network errors can cause this problem, and it will take time to check the details.
The best solution at the moment is to change the browser or switch to another network