After a lot of investigation we are finally confident about the source of this issue. The root cause is in a 3rd party framework we use to perform requests to our servers (to download imagery and elevation tiles for example). We have reported the issue to the 3rd party but it might still take a while to get a fix.
In the meantime, we are attempting to find a workaround but it is a fairly delicate piece of code that is hard to change without potential side effects (adding more bugs).
We will report back once we find a workaround.
Thank you for your continued patience.