I've had this pesky issue for months now. The only significant change has been that I have moved all my Environments from Windows to Debian 11 and Raspbian.
The issue is that quite often flows will not load fully load without manual refreshes. On loading a flow, I get this screen instead:
If I refresh the page as soon as I see it, I will then have to refresh 2x or 3x times in total before the progress bar fully completes and the flows are visible and ready to use.
If I wait for a while and come back to it, only 1 refresh is required.
Sometimes it looks like it has loaded after 2x refreshes, however the default editor does not show any syntax highlighting. After a 3rd reload the syntax highlighting works again.
I have checked the developer console and an incomplete load looks like this:
I've just started the migration to 100% NR for all my home automation and have a tonne of things to fix/redo/configure.
Interestingly, moving from a 300 series to 500 series controller has surfaced issues that didn't exist on the 300 series controller e.g. wake up beams.
All of these issues take time to investigate and come up with a plan to resolve, in this case - replace the offending 300 series devices, as the manufacturer will never provide a firmware update to resolve the issue.
Anyway, I'm going off topic. Thanks for your help.