Thanks all for the advice. I really appreciate all your responses. I'm kind of committed at this point to the external SSD but I will make it a priority to upgrade in the future. So the problem did repeat itself a few more times (luckily there was no corruption), but i have now managed to DL the chain and BTC core is running happily at the moment. The issue may have been (bear in mind I'm no expert) that the USBC connection was letting me down thanks to the UAS protocol... because when I switched to a old style USB connection the rest of the DL went fine and my node is running fine at the moment. I wonder if the heightened demand of the DL also played a part? Suffice to say that using an external drive may be more trouble than its worth.

Thanks very much, when I saw the word “fatal” I feared the worst. But I will try your suggested actions and report back.

Thanks for the quick reply! Do I just relaunch btc core and start again then? Or could it be that I can pick up the dl where it left off? Not sure how to proceed…

Bitcoin Core 27.1 (linux tgz 64bit)
Linux Mint Cinnamon 22
Intel Core i5-7300U CPU @ 2.60GHz × 2, memory 15.5 GiB, Hardrive 512.5GB (plus external samsung T7 SSD for Bitcoin core installation).
The BTC core GUI threw up a fatal error with roughly 7hrs of DL left of the block chain! Plus my external SSD was no longer visible on the computer (so I yanked it out and re-connected and then it became visible again).
Beginning of debug.log: https://pastebin.com/Zg8ZCDQ6

FYI: I am a novice at Linux and a journeyman at best with IT 
Thanks