Hey Mountrobson,
Those are great steps and can resolve many odd issues related to the built-in keyboard features. If you haven't already, make sure your iPhone is fully updated. The description shows you have iOS 16. The current iOS version is 16.2. To see what you have installed, tap Settings > General > About. If an update is needed, be sure to back up first: Update your iPhone or iPad - Apple Support
Update your iPhone or iPad wirelessly
1. Back up your device using iCloud or your computer.
2. Plug your device into power and connect to the internet with Wi-Fi.
3. Go to Settings > General, then tap Software Update.
4. If you see more than one software update option available, choose the one that you want to install.
5. Tap Install Now. If you see Download and Install instead, tap it to download the update, enter your passcode, then tap Install Now. If you don't know your passcode, learn what to do.
If the behavior continues or if you're already updated, do you have any third-party keyboards installed? To check tap Settings > General > Keyboard > Keyboards. If you see any installed here, temporarily remove it to see if the behavior continues. Here's more details on those steps, just in case: Add or change keyboards on iPhone - Apple Support
Let us know how it goes.
Take care!