Severe lagging

I know this issue has been brought up before, but I haven’t been able to find an answer. My old game is at level 421, and I play on an iPad Mini that’s about five years old. I have absolutely no problem playing on this device. My other game is on Samsung tablet E and I’m at level 122. This tablet is only six months old, and for about the last month, the game lags constantly, and I quite often get disconnected from the game. I’ve tried finding an answer to this problem in the forums, however, all I find are the complaints, but absolutely no answers. I’m not sure what I’m doing wrong in not being able to find the the answers to the problem but if someone can suggest a fix, it would be greatly appreciate it! Thank you!