Z-wave repeater chaos

I am hoping to get some pointers, I moved over from Smartthings a few months ago and have a predominantly Zigbee setup - apart from a Yale Conexis L1 lock which has a z-wave s2 module in.

On the advise of multiple posts (and to make the mesh more redundant) I have tried to add mains powered switches as repeaters but each time the z-wave network goes bonkers after a few days, the lock flip-flops between direct access to the hub and via a repeater, then after a few days the repeaters become non-responsive, needing a power down and power up cycle of the Hubitat c7 hub

I'm in the UK and have tried the following devices:

  • Aeotec Smart Switch gen 5 (z-wave 2)
  • Devolo Metering Plug TM:2655.

all of which were super fussy to get set up -needing to be right next to the Hubitat box to pair. Should this be working? and can anyone recommend any decent repeaters for the UK market?

Currently the setup genuinely seems more reliable without the repeaters and. all round the Hubitat z-wave experience on the C7 feels a bit beta.