Slow performance after update ios13

Well, I use 2- language keyboards. Everything are smoothly with English but for Vietnamese part, it takes me 3 second whenever I Put special accent sign. So image that if I write sentence with 5 words then it takes me 25 seconds.

the slow feedback of keyboards cause grammar error and when I click backspace to erase it takes around 5 seconds to finish command.

I think this version only got problem with Vietnamese language.

So in general, I type faster than keyboards respond.