The IRS only knows what is reported to them. How what is the date of the check, oftentimes these checks are only good for like 90 days. Your 1099-R says it is a rollover. Rollover has no tax consequences. The IRS does not know if you cashed the check or not. The fact that you never rolled over the funds or cashed the check, I am not sure what happens going forward. My suggestion is that you go back to the place that issued your check and talk with them.
