I'm also having this issue and we have just isolated it to the extend that it happens in the newest shared hosting package that my hosting company offers. We realised that MODX sites on their "Next Generation" (https://blacknight.blog/next-generation-shared-hosting.html
) shared hosting package have loads of issues with saving, resulting in that endless loop when you want to save a new resource or make any changes. It makes it pretty much unworkable.
I have made a blank test install - no extras or anything. A simple, blank install with just the Base Template and I will get the endless saving loop if I try to save a new resource. If I refresh the page, the resource is saved. However, if I then try to change the template, e.g. to (empty), I get the loop again but this time on refresh get an error message and the template change has not been saved:
Code: 0 communication failure
Quick Update does let me change and save a template without any issues. However, neither of the two workarounds are acceptable to pass on to clients!
A MODX site installed on their standard, older shared hosting package on the other hand works perfectly fine (they don't even sell that anymore but I still have an old account with access to it).
The issue for me is that the NG hosting is preferable as it is a more stable platform and offers site isolation, preventing sites from being affected by traffic surges on other sites. It has made a great speed difference for us on non-MODX sites so we obviously would like them all hosted here. Anyway, for now I have no idea what might be causing the problem on the NG hosting but any suggestions are welcome or advice about what questions I should ask the hosting company to help identify it. Thanks!!