That's up to Google

 

In what way hasn't it worked? I use it rarely, but it's always seemed to work when I do.

But yeah, we are just users and have no influence with Google. If a keyboard app doesn't work for you just switch to one that does - there's never any point putting up with an inadequate app just because that's what the manufacturer installed.

 

https://f-droid.org/packages/rkr.simplekeyboard.inputmethod

https://f-droid.org/en/packages/org.pocketworkstation.pckeyboard/

 

If you've having you are having a problem with this for three years, this would appear to be more of an issue with you need to address on your phone, as opposed to being 'something should fix'. (There do not appear to be any widespread online reports and articles stating this is common problem.)
Have you tried clearing the Gboard app cache? Also try long-pressing on the Space Bar, a 'Change Keyboard' dialog window should pop up, where you can add/delete different keyboards (English, Spanish, etc.) and a button to the Language settings menu.