Battery drain on iPhone Xs from iOS 13.5.x to 13.6.1

[kiddingguy]

Since early iOS 13.5 [end of May] I have a huge battery drain on my iPhone. Cannot specify exactly what's going on... iOS 13.5.1 should have fixed it, as well as iOS 13.6 (though others said 'otherwise') and maybe even 13.6.1 released yesterday.4

In some instances I lose 5-10% in 1 hour/1,5 hours on idle mode.

 

Battery stats gives the latest 2 weeks 'Phone > Low signal' (around 20-22%), but according to tests from my carrier reception should be fine. I haven't used my phone any differently on apps or usage.

Battery health is 99%.

 

I do have Apple Care, so I am able to Express Replace this iPhone. Is it wise? Or are there some other troubleshooting things I can do before swapping?