Jobs being disabled in v1.8.6

Jobs that have always run suddenly are showing DISABLED, with tooltip: “Cron expression is invalid or don’t have any occurrences over the next 100 years”. I followed the advice for the thread " Job keeps getting disabled" which suggested to upgrade to v1.8.5. I upgraded to the latest 1.8.6 and have this issue. It seems like something changes the Cron expression month and day to 0 0 31 2 * (adds the 32 and 2, which disables the job). Is this a regression or can anyone please suggest a fix? Recycling the app pool (IIS) fixes them for and then they eventually become disabled on their own.

A fellow developer suggested to delete all the Hangfire tables in the database. HangFire automatically recreates these tables when it runs again. Losing hangfire job history was a tradeoff to having my jobs not disabling themselves.

Removing the tables worked in my situation, but leads me to believe that maybe the upgrade to 1.8.5 solution worked only because the Hangfire data was cleared, by co-oncidence. A clue may be in historical data.