I noticed that when the screen is locked on the phone with a MTS SIM card (UMS), various kinds of advertising constantly appear. Which is actually annoying, and also affects the battery charge.
To disable it, open the SIM card menu (SIM menu) – MTS Click – Activation – Disable.
To disable / enable SMS advertising coming from MTS, you must send an SMS with the word STOP to a free number 10250.