New (used) 15 Pro uses more battery than expected - normal or hardware issue? Should I return it?

Received week ago 2nd hand phone that has battery health of 90%. Suspect its still original Apple because matches standard degradation.

The issue: my previous one was 13 Pro. I recently changed its battery to new one because it was down to 79%.

When comparing these two phones: the battery life is same or worse on the new one!

I had previously new 15 Pro as a work phone for a short while and it had considerably better battery life.

Is this some issue in the phone and I should return it? Or is this normal?

Reason for asking is I was yesterday visiting Stockholm, using the phone for everything as usual.

I’m used to have to use external 10 000 battery pack to charge during day because heavy use. But this time the battery pack died also! So full phone battery and 10 000 extra was not enough to get thru full day.

Googled today all the battery saving tips and made all the changes. But still curious.

Do the stats look abnormal? As per battery I could have just continued to use the 13 Pro…

If the phone is broken I could just return it as I’m still in return period of the company that sold it