Further to my reply to Todd's question.
Hello folks,
I feel like I've made some progress. Sorry it's so long but you need all of this info. I really appreciate your help.
I was ready to throw the computer out of the window, I uninstalled Reaper and reinstalled, still the same issue. Did it again and still the same so I thought I'd look to see if Reaper had its own uninstaller as I thought something was lingering around somewhere as mentioned by Mertay. There was no dedicated uninstaller BUT in the start menu under Reaper was a link saying "reset configuration to factory defaults", I clicked this and started Reaper and I got my waveforms back.
Problem was my track then didn't have the icons on it as before but, some came on when I armed for recording.
Track unarmed:

Track armed:

I then imported a configeration from 2018 and I lost the waveforms again BUT my track looked how I wanted it to like below, at this point, it started creating the peaks again, it seems to constantly do it every couple of minutes::

After all of this messing about I've come to a conclusion and please tell me if you think it's a load of rubbish.
When I had this new laptop, in August 2019 I installed Reaper 5 on it, in imported the config from 2018 which was still Reaper 5. So when I upgraded to Reaper 6 it migrated the settings fine.
This time, after reinstalling Win10, I put a fresh install of Reaper 6 on (no Reaper 5 legacy)and when I import the config, there are conflicts.
If you agree that this is the case then I might install Reaper 5, import the config, upgrade to Reaper 6 then export the config. I had a lot of SWS functions working and it took a while to get it working.
What do you think?
I'm feeling better now because at least I can replicate the issue.
One question, I've forgotten how Reaper used to work after having all of this hassle. If armed for record, should the signal still get into the track (dry straight from Focusrite 18i8) if I have the input gain at zero on the Focusrite? The signal does strengthen when I turn the gain up and I can make it clip easily.
If you can explain why the track has the "route" icon missing and a couple of others that would be great. I don't remember ever setting that up. They all come back when I import the config but obviously that gives other issues.
Thanks for all of your time with this issue, it's been a big ball ache and is still on going but i feel we are making progress.
Cheers
Stay safe
Phil