@zafkzrckq3hy Ok - so from the video that posted - aside from having to point out that you made at least two tackle ...
Do you have auto-switch turned on? If you are having trouble getting players to the tackle, then maybe switch it off and select your players.
You have the sprint/tackle button held down the whole time and the direction button held the whole time ... try heading towards the player with the ball and then holding only the sprint/tackle button (ie. finger off the direction button).
There is also a slide tackle button and a hard tackle button (sprint/tackle held to the left ... i think) ... try using the tackle buttons as well as your tactic of running into the player.
Also - it looks like you are on h2h - there can be all sorts of issues with button delay, even if you have a "green connection" that have to do distance from the server ... this would explain having the issued on different devices and different accounts. My h2h is terrible - but i am a long way from the server, so it just is what it is.
Do you have the same issues in PvE as you do h2h?
(Sorry for all the questions - just trying to trouble shoot - as it doesn't sound like a device or account issue if you have already checked across multiples of each)