I use a hair clip to keep the cable well well connected to the watch. You can buy the hair clip anywhere for less than a dollar. Try it. It works!
However it is frustrating for a 800$ Garmin watch. I sincerely hope that they correct this error in the new models of Fenix.
I have a Garmin Fenix 5X and vivoactive. Both have the same hellish con reaction as the 6X. I have to clean the brass contacts constantly to get them to charge. I have a friend with a 6X solar and he’s already having the same connection issues. It would stop me buying another one.
I have to clean the brass contacts constantly to get them to charge.
I find that is avoided by ensuring the watch is washed after use and dried after it gets wet and before putting it on charge.
Of course cables wear and that is to be expected over time. But FWIW I still have watches with perfectly clean connections and charging cables that are at least a couple of years old. I do also have some that have had to be replaced too.
You can use pliers to squeeze the contacts a bit. Helped for me. Also, Garmin will probably send you a new cable when you ask them - they did it already once for me (free of charge at least). But sooner or later the issue will come back.
I 100% agree, at the price point of the watch (or better: of Garmin watches in general), this is unacceptable.