One-handed Keyboard setting not staying on iPhone 13 in Messages

I prefer to use one finger to type in Messages on my iPhone 13. However when I set the Keyboard Settings to One-handed Keyboard, it won't stay at that setting and I have to reset it several times even during the same text! That's extremely annoying! Is there some way to make that One-Handed setting as permanent as the other Keyboard settings are?? And if there isn't, why isn't there! My (left)-handedness isn't going to change any time soon!