Online experiment not running (404, 405, not syncing, not uploading, freezing...)

Hi,
I’m at my wit’s end. I’ve been experiencing all sort of issues with my experiment.
To begin with, at first, my experiment didn’t run locally because the program couldn’t find the audio files that I was using. I solved the issue by recreating the exact same experiment in the exact same way and now it runs locally without any issues.
After this, I felt confident that it would work online but I’ve been encountering all sorts of issues.
The main issue at the moment is that it seems like the files are not uploading to Pavlovia so when I run the experiment I get this error message: Failed loading audio file with status: 404
I checked the settings based on what I found online and they should be fine.
At first I was using Safari as my default browser so pavlova automatically opened there. As I’ve experienced issues with Safari before, I changed to Chrome. The first time I tried in Chrome the experiment started and played the first audio, then it froze. After that, when I tried again I got an error message (404 or 405, I can’t remember).
I tried again a few times and I sometimes get the following:
108.5796 EXP Imported “pass to excel sheet” as conditions, 31 conditions, 3 params
111.3106 INFO Successful sync at: 22:17:01, took 1.353s
<Response [405]>
Although, it says the sync was successful, I can’t see my files in Pavlovia. Often times, it seems like nothing happened and my experiment was not created but if I refresh the page a few times it’s there, but without the audio files.
But then, on different occasions I get the 404 error message.
What is interesting is that I didn’t change anything in my experiment but every time I try to run it I get a different error message.
Psychopy also froze several times and I had to force quit or force my computer to restart.
My files are in wav format so it shouldn’t be the issue in my understanding.
At this point, I’m just very confused and ran out of ideas what I should try, so any suggestions are most welcome.