Why is my Apple Watch only showing time and a red light?
How can I get watch to show face again only shows time and red lightening
[Re-Titled by Moderator]
Apple Watch Series 5
Has the battery of your series 5 ever been replaced?
If not, the battery might be at the end of the usable lifetime and needs to be replaced by Apple.
Apple Watch Service and Repair - Apple Support
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copied from: If your Apple Watch won't charge or it won't turn on - Apple Support