when a phone leaves a “default state” it will get harder to compare power profiles, when just one app can make the difference - or a weird home network or mobile connection can skew measurements. This being said, I’m surprised enabling
Airplane Mode => No Change (2,5% battery drain per hour)
doesn’t change the discharge rate for you - unlike my own experience when debugging a “the discharge rate is too damn high” FP3. battery-historian can give you lots of insight just by the power of visualization.
Example: this screenshot of battery-historian shows a period when wifi is disabled and discharge rate drops to ~0,4/hrs levels. With an active wifi connection it is at ~1,8/hr rate what is still too high, but less than 2,5%/hr (after resolving two other issues). This is pretty much a default install /e/ (0.18 on Android R already, most current firmware) - no further apps.
if you can, give it a go. If you can’t, BBS is a good AccuBattery alternative, as it doesn’t shy away from terminology.