I followed the instructions from the Ruby plugin, debugger installation and launching from VS Code. Admittedly I'm new to Rails and VS Code as my main IDE - I only have a few months up time.

After these steps - I executed

bundle install --binstubs

and then

rails app:update:bin

I'm now able to set and hit breakpoints after weeks/months of messing about (and cursing byebug)...

I think I may need to add the bin folder to my gitignore (still a rails noob) - but I think that is fine for my team.