OK. Yeah, a DCS of 677 might be a problem.
I know you said you are using this Baofeng as a way to learn about radio, but they ARE really crappy radios, and without proper test equipment to rule it out, I'd consider the fact that it may be far enough out of whack to not work correctly. We had some show up at a work site. They started complaining that the "repeater system was crap" Repeater wasn't perfect, but on a good radio is was fine. On the Baofengs is was nearly unusable. I put the Baofengs on a service monitor and they were all over the place.
In other words, I'd suspect any issues are on the Baofeng side.