So the "glitch" was halving your break time, or was there anything else that interfered with your answer choices? For example, there is a somewhat common glitch, where the system does not register your answer choices -- AAMC explicitly mentions this glitch before you start the test, so you cannot argue against this. You're responsible for double-checking all the answers.
Also, what do you mean by "scored exactly 50% of each of the four sections." AAMC is scored based on percentiles, so there is absolutely no way of knowing how many problems you got wrong based on the score you receive. Say you "know" you got only 10 problems wrong on C/P, but you can still receive 125 if everybody else also did well. Everything is scored relative to the median.
Looks like they already rescored your exam. I don't think receiving a re-score via USPS will make any difference, especially with COVID-19 where mailing or any in-person consultation is discouraged. I wish you the best of luck.