I passed on y’all’s information to support. They asked me to retest it today so I’m guessing the developers are making changes to fix it. Here are my results. This time I also recorded the times.
(Tell you I’m unemployed without telling you I’m unemployed with x conditions) : 
I’m also including the time because someone of you mentioned your’s was slow and I wanted to see if it was a similar time or longer.
The first save refers to where you choose the file. The second save refers to where you type in details and choose the category.
Safari. The creator app was not installed when I tested this.
1st save:
it took 50 seconds then I got the watchface error (If you need this again just ask)
I Restarted the computer and cleared the history of safari
This this time
1st save:
45 seconds until watchface error
Tried a different file
1st save:
55 seconds then the watchface error.
Chrome
1st save:
50 seconds then watchface saved message.
2nd save:
Then Typed in the details and saved it on the next part took 60 seconds
After that, it showed up correctly in Facer and I was able to sync it to my watch with no errors.
Firefox
1st save:
1 minute 5 seconds then watchface saved
2nd save:
1 minute 10 seconds to go to make the second save and show the screen with multiple watch pictures.
MS Edge
1st save:
48 seconds to watchface saved
2nd save:
55 seconds to show up watch
Saved correctly and synced with no errors
Arc
1st save:
50 seconds to watchface saved
2nd save:
1 min 3 seconds
Saved correctly synced with no errors
Vivaldi
1st save:
35 seconds
2nd save:
38 seconds
Saved correctly synced with no errors
Sidekick Browser
1st save:
40 seconds
2nd save:
40 seconds
Saved correctly synced with no errors
Reinstalled the app today
App
1st save:
45 seconds watchface error
640 x 780 was a little smaller unlike the web version
Try another file and expand it to make it fit to see if that made a difference
1st save:
40 seconds watchface error
I Restarted my computer but it didn’t make any difference
1st save:
40 seconds watchface error