I have the same issue with my venu square watch. No matter how many times you sync it with Garmin connect, it keeps popping up a message that says "memory low. Upload to Garmin connect".
Unfortunately it does not appear there's any way to upload a screenshot which I have to show this.
Unfortunately Garmin has terrible support files so searching for the phrase low memory does not help. Look for deleting personal records for your device and that should help
Look for deleting personal records for your device and that should help
Deleting activities as suggested in the linked articles is the best way to free up some space on the watch. Personal records, in contrary, take just a few hundreds of bytes, so it won't help much with memory
If deleting the activities (history) is not sufficient, you can delete the content of folders //GARMIN/Debug/, //GARMIN/RemoteSW, and unneeded fiels from //GARMIN/Text/, //GARMIN/Courses/, or //GARMIN/Workouts
Going by the using the PC instructions there is nothing listed in the activity folder at all. I did delete other files you mentioned but none of them were more than 2kb each and very few of them.
It would seem if this is a problem where the memory fills up garment should have some built-in way to flush it or at least make it very easy to do so.
