Quirky question marks

When I type a question mark in iMessage I don't always get a question mark. And yes, I know I have to use the shift key. I have an iPad 2 16GB running iOS 9.2.1, but my issue has been happening since iOS 8 or maybe even before then.

Examples:

- Trying to type a question mark all by itself always gives a period. I have to type it twice, which gives ".?", and then delete the period.

- Typing certain questions sometimes--but not always--causes the question mark to come out as an exclamation point. For example, at times I'll get "Are you!" instead of "Are you?". When that happens, if I backspace over the exclamation point and type the question mark again, sometimes it works, and sometimes I have to repeat a third time. At other times it works right the first time.

This is a minor annoyance, but it would be nice to be rid of this behavior if possible. Does anyone know how to fix this? I haven't found it mentioned anywhere.