You can try a factory reset. You can install the battery upside down for 10 seconds or simply short out the two terminals with the edge of the battery for 10 seconds. (Don’t bend the pins down by pushing too aggressively.)
The new battery could also not be up to par.
I’ve discovered over time that I get much better results with my Stages if I use top tier, name brand batteries that are fresh - Duracell or Energizer. I used to buy cheap 10 packs of batteries on Amazon and my results were mixed. I once had a new Energizer that gave me problems.
ADC is dependent on temperature so it will vary. 1885 watts peak is a possibly real reading but if you think it’s not then contact Stages support. They are very responsive and will likely ask for you to export the ride data and send it to them. If it doesn’t look right they will repair or replace your meter.