Watchfaces for personal use only

Sorry if this is a really dumb question, or has been asked before.
I have made myself a watch face. It’s a very minimal face, and I don’t want to try to sell it or anything, I just want to use it on my watch. I created it a year or so ago, and loaded it onto my watch (Gear S3). After about 6 months it disappeared off my watch. Don’t know why, but one day my watch had a different face and I couldn’t find my watch face anywhere. I loaded it onto my watch again, and a few days ago it disappeared again. I have just loaded it back onto my watch, but I was just wondering if I am doing something wrong that may be causing it to disappear?
Is it enough to just do a ‘run on device’ from Galaxy Watch Studio, or do I have to upload my watchface to the store and download it from there? It is such a basic (and therefore quite embarassing!!) watchface - it just has the time and date, steps, battery and heart rate, with no animations or anything. I deliberately kept it as minimal as possible to try to maximise battery life, but I really don’t want to share my (quite poor and childish) work with anyone else, and therefore don’t want to have to upload it to the store if I don’t have to.

Hello, with GWS or GWD you should always be able to load your watch face (or faces) on your watch, without the need to upload it to the store first (if you did not publish in past, they would not let you start right now anyway, you would have to pass a contest for that). I have many of my own watch faces on my watch for years and they did not disappear, unless I deleted them.

The only time I’ve heard of that is when your watch runs out of memory. I used to test a lot of watch faces and would have mine bumped off occasionally. If I test a watch face now I delete it. If you have a lot of extra apps or watch faces remove those you don’t need.

Samsung Developers Relations

Thanks for your replies. I think you may be right re the ‘a lot of watch faces’…I just can’t help myself when I see those ‘now free’ faces on the Samsung store, plus, I did notice that my watch would exhibit lack-of-memory symptoms each time my watch face disappeared - it would become extremely slow, almost to the point of being completely unresponsive. Anyway, I have deleted all my extraneous watch faces and I’ll see how things go.
Thanks to you both for taking the time to reply.