Autocorrect changes words even after I deny suggestions

On both my MacBook and my iPhone (13), I frequently face an issue with autocorrect where it will suggest a correction or change to a word I typed, I will click the "x" on the pop-up to deny the change, and then when I hit space to type the following word - or sometimes after I've finished typing the following word - it will still make the suggested change anyway. In many cases, I have to fight with it and retype the original word several times over to get it to stop making the "correction" even after I deny the change over and over.

Has anyone else faced this issue, and do you know if there is a way to fix it without disabling autocorrect entirely?