Is telegram or the 0.12 update that drains my battery?

All is in the title.
I’ve installed Telegram under Shelter right after the 0.12 update, so I wonder on which is the responsible for the dramatic increase in battery usage.

I’m now at 49%, while I was used to see a figure around 70% at the very moment of the day (dinner time, 19:30 - 20:00)

The reason for battery drain could be nether of them two or both- I have the same config an no extraordinary bd. Did you change something else?

No. Only TG and the update

I had a drain problem after dirty flashing from Nougat to Pie. A clean install solved the problem. Maybe an option for you?

Not at the moment. I’ve flagged "not to work in background"in TG, just to exclude an hypothesized cause of bd

I had the same issue when I installed the 0.12 Q update for Oneplus 3T: flashing the latest 0.11 build fixed the battery drain.
Probably this is one of the reasons why the update was taken back a couple of weeks ago.
I suggest you to flash 0.11