If it's been less than 60 days since you took the distribution, the distribution wasn't reportable on your 2019 tax return in the first place. Also, your 2019 RMD is based on your 12/31/2018 balance, not your 12/31/2019 balance. It's the waived 2020 RMD that would have been based on your 12/31/2019 balance.
If your deadline for taking this 2019 RMD was 12/31/2019 because 2019 was not your first RMD year and you did not take the RMD in 2019, it's still a late RMD that needs to be reported on 2019 Form 5329 Part IX and, if now taken in 2020, cannot be rolled over, otherwise you can't request a waiver of the 50% excess accumulation penalty for 2019.
If you are taking about having recently taken your RMD for 2020 within the last 60 days, that can be rolled over, assuming that it would originally have been eligible for rollover if it wasn't an RMD.
