I have contacted Santi and he has graciously helped as well.
I suspect - as you have suggested - that it is an issue of conflict btw Obsidian and G-Drive when syncing.
I have reinstalled Obsidian and cleaned up the jungle of ghost files/folders.
Hopefully, it should be back to normal. For the time being I will do without Logseq.
I am very grateful for your kind help.
Best regards -