So I believe I have fixed the issue, I'm just making this post in case anyone else has a similar issue.

For the longest time my Civic locked with the fob only maybe half the time. I thought it might be the battery in the fob, except that it ALWAYS unlocked it. I chalked it up to possibly the lock button on the fob having an issue.

This got worse and worse over the last month or so until really the only option was to lock it manually with the key. Coupled with this, my turn signals slowly began to go out. Sometimes they would flash 10 times, sometimes 30, sometimes only once. Their performance steadily degraded to the point where using the turn signals was more or less useless.

After replacing the flasher relay under the dash, both issues seem to be resolved. I have no idea why the power locks would be tied into the turn signal relay except that they flash when you lock it, but there it is. Since I replaced the relay it has locked every single time without fail.

I hope this might help someone!