@Jici and @sudsy thanks so much for the help and answers.
As it turns out the issue only happens with Chrome and not on Safari.
Still strange to me that during the Initialize call the issue (even in Chrome) doesn’t exist since somewhere the file name gets set to equal api_inilialize_file whereas for any subsequent calls it gets set to equal conver.ashx.
So somewhere Bubble does override this during the initial call but my guess is that that place isn’t exposed to users.
I’ll look into cloudconvert as well to see if that could help solve it.
Thanks again