since for all the others the client seems to run fine, maybe, and I say maybe, it is your system that is rubbish.
No, nothing wrong with the system. There's a problem with my account - while I've followed the process to the letter to link my Epic account with my new Frontier account (which is valid btw, I can log into "My Account" just fine on the website) for some reason the linking of the two accounts has failed and I cannot do anything to try again.
Edit: Sorry, just realised you quoted an earlier post of mine. A subsequent update of the Client fixed things - even though I'd
just downloaded the thing moments earlier. Perhaps something went wrong - the Epic Client was very unstable, yet it's fine now - it's the FDev launcher (the custom Epic one) that doesn't recognise my purchase. I'm NOT going to play about with the regular launcher on my main gaming PC - I'm keeping that totally separate!
Scoob.