In Edit Config-Scenarios-More, there's an option called Aim Stabilizer, see if it is turned on. Turning this function on may affect the input delay. I saw the video you sent, I don't understand Russian, sorry about that.
And I see you use S1 on PS5 with PS5(P5 Mate) mode, you're using a P5 Mate, right? How about making a test with the PS4 version of Apex Legends, using S1 with a PS4 controller?