Same here on LG G6 Android 8.0
EDIT: Oh well, I think I'll elaborate a little further. I don't remember when it all started since I dropped out during transition from line and only got back recently, but after I got back I do get occasional performance drops when FPS drops down for shorter periods like 20s. It seems to happen more often in extended play sessions (but sometimes happens even on "fresh" application restarts), and also I believe happens more often on both Sekhmet's Bath stages, but especially on the bloody one (but can also happen on any other, just subjectively less frequent).
After 2.6 I also started getting occasional screen freezes for about 2-3 seconds accompanying fps drops (the game itself goes on in the background, you typically get back mid enemy combo) which happen only in extended play sessions (then again, they just happen very rarely, so maybe i just didn't catch any during casual play).
I dug up a random cpu activity monitor in play store, and during the performance problems displayed CPU utilization does not show any abnormalities.
I put all possible graphical settings (lighting, resolution) to lowest both ingame and in some android game mode thingy to no avail.
With 2.7 rolling out aforementioned FPS drops are pretty much permanent from game start.
UPDATE: I nominate Doublicious + Sekhmeth's Bath bloody version as the worst offender. It's so bad even input doesn't work properly (like she leaves block a couple seconds after you release it and does a charge attack instead of L5 mash). Though Doublicious is consistently bad at all stages. Meanwhile CPU usage stays around 20%.
