Paste from PDF in Preview creates gibberish after annotations

I've seen several posts about this but have not been able to find an actual solution and it would not let me reply to any of the posts...

I open a PDF in Preview. It functions just fine (I can copy and paste normally).

I then make some annotations (highlighting, adding arrows etc...)

I save.

I open the file later to make more annotations.

I can no longer copy and paste. Well, I CAN but it just pastes nonsense. If I open it in Acrobat Pro, it acts the same way.

I first noticed this when using text to speech. I often have my computer read to me as I follow along highlighting as needed. I do a lot of research so the text to speech option saves my eyes sometimes. Anyway, the text to speech works the same as the copy/paste. It reads just fine at first, then after some annotations, something slips up and it starts reading the same thing that it would copy and paste. For example..

"Ten Reasons for IT Educators to be Early Adopters of IT Innovations"

becomes

"./%(@/&A"%A()"$(*.(45#0&,"$A(,"(B/(( 4&$'3(C5"D,/$A(")(*.(*%%"E&,-"%A("

Help?