I'm 90% sure it isn't on SE's end. I don't use a mouse on my PS4 for this game but I DO use a keyboard. My roomate does the same and we both have problems where our keyboard is "laggy". If we type too fast it doesn't register some of the key presses at all, or even worse, it'll literally type random gibberish, keys on the other side of the keyboard I hadn't even pressed. I once had it repeating "kfjh kfjh kfjgh" or something similar after typing really fast, it repeated itself 50+ times somehow.

I'm using a wired keyboard and my friend is using a wireless and we're both having this issue. I use a PC monitor for my PS4 and have absolutely zero issues with input lag on a controller