I am disappointed that no one wants to help . I spoke to customer support all day and basically they don't know what to do and don't have enough knowledge to resolve complicated issues. I don't know what to do but looks like I need to return the watch because not working with Samsung phone.
Have a few questions to ask is your phone a import as don't recall s20 ultra 5g having snapdragon though the uk model was exynos. If its a import this maybe your issue you could be having. As when you first set up the watch it go's to regional information. When it does this it knows and phone knows what it can and can't support ie if a uk phone runs exynos the watch knows this as you set uk regional setup. Now if its a import the watch knows this information and knows it should not be a snapdragon chipset. I have fold 2 and both uk and Europe have snapdragon chipset in them so watch knows this information. If this makes sense to you.