I couldn't post or vote yesterday it appeared on steemd.com that I had negatice RC so I think your premise of negatiuve RC based on usage the previous five days is correct and that has been posted by Steemblog witness as an explanation and the patch 20.03 is to produce resource credit debt forgiveness and return us to zero RC, which of course regenerate every day. So today with the patch HF 20.03 I can post again, but my voting power is still in the 18% mana range (The new term for voting power), which will regenerate on it's own or I can power up new steem purchases or buy/lease steem power and increase my mana, so I am waiting for 3 days and 19 hours to get back to 100%. Your mana power percentage and your resource credits levels can be found on steemd.com.