Blurry out of focus image in Develop module

Hello. I have an issue that was reported and experienced by others a few years ago and thoretically has been resolved, however......!

I am using LR Classic 13.0.1 on my MacBook Pro M1 2020 with the lid closed (clamshell mode) and an external monitor (Eizo ColorEdge CG223W). OS is Ventura 13.2.1

When I view an image in Loupe View in Library Module, the image renders fine. When I select Develop Module, the image becomes blurry (kind of out of focus) and doesn't render.

I've done some Googling and found that the workaround was to turn off LR's use of the GPU. I do this and the issue resolves, but then when adjusting sliders in the Develop Module, the image blurs as the adjustment is made, then renders properly again once I stop moving the slider (so I can't view the changes 'live' as I make them). If I revert to using the GPU, the sliders work as normal, but the out of focus image issue described in the paragraph above obviously returns.

Can anyone please offer any advice here? Is it that the GPU isn't compatabile/not powerful enough for LRC, or is there an issue with the monitor? It's quite old now. FYI, this issue does not happen when I am using the laptop screen with no external monitor.

Many thanks for the help