Apple Watch Ultra Battery Life

Your Apple Watch Ultra is less than 1 year old so by definition still in warranty cover if it has a problem.

It doesn't matter if anyone else sees something similar because every Watch has different settings and usage. Sometimes after a software update on any computer device the battery load is higher than usual for a few days while it reindexes everything, then goes back to normal. Start by making sure your Apple Watch is fully charged then use normally and see how long it survives before low battery. Repeat a few more times to get the pattern, then if you have confirmed the problem is still there Contact Apple Support and arrange to get the watch and its battery checked by Apple's specialists.