Here's a cut and paste from the Strat email.
Thanks for your message. On Sunday night, March 8, we implemented new code to support the set of changes that constitute Bullpen v3, which is only supposed to apply to the new 2019 season at this time. Unfortunately, one line of code pertaining to new additional rest days for overworked relievers managed to slip past the boundaries of 2019, and the result was that it was in play for a fair number of leagues in other player sets, including ATG 8, for Sunday night's games only. To be clear, this was not intended, it has been patched, and it will not affect other player sets (besides 2019) going forward. We're sorry that this occurred.
Sincerely, Strat-O-Matic Baseball 365
http://365.strat-o-matic.com