I signed up for the X Box Game Pass before the MFS 2020 release date to pass the time playing Wolfenstein until MFS 2020 came out. I purchased and downloaded and started playing MFS 2020 with no problems. Both games are listed as owned in my Xbox Game Pass.
I cancelled Game Pass before the second month billing.
THAT is when MFS 2020 started asking me to "install disc one" before letting me play.
I just tried resubscribing to Xbox Game Pass (at $4.99/month - the $1.00 a month PC/Console combo jumps to $14.99/month the second month!) and NOW IT IS NOT ASKING FOR THE DISC!
It is criminal that this work around forces me to pay $4.99 a month for something I already paid full price for, but I'm willing to pay $4.99 to play for the next month while Microsoft sorts this mess out. (I have put in two call back requests with customer service, estimated call back times of two minutes and 44 minutes, never received a call back either time).