RasPlex needing insecure connections

My problem is Plex can see RasPlex on my Raspberry Pi 3b but Rasplex can’t see PMS.
I’ve been usung RasPlex via Plex for many years. Some time ago there was a secure connection certificate problem and I had to change Plex / General to allow fallback to insecure connection ‘on the same network’ and Plex / Network secure connections to ‘Disable’. Since then I have not updated PMS or Plex for Windows. (PMS 1-25-5-5282 PfW 1.44.0.2981).
I’ve just had to do clean install of Windows 11 and these versions don’t work well. I’ve installed the latest versions and set the Plex / General as before and the Network option to Preferred (Disable is no longer an option). When I launch RasPlex on the Raspberry Pi all I get is ‘Search’.
PMS and PfW are on the same PC with Cat 7 connection to the router and RasPlex is wireless then HDMI to the TV. I’ve also tried adding SSL .3, TSL 1.0 and TSL 1.1 i Windows.
Debug level is set to Disable and won’t stay Enabled !
Are there any other attributes I can change or do I have to go back to the old versions?