> "The conventional gaming device or client station must be in the idle mode with no errors or tilts, no play and no credits on the machine for at least 4 minutes. After this time, the conventional gaming device or client station must be disabled and rendered unplayable for at least 4 minutes. During the time the machine is disabled a message must be displayed on a video screen or other appropriate display device notifying the patron that the game configuration has been changed." — Technical Standards for Gaming Devices and On-line Slot Systems 1.140
https://wizardofodds.com/ask-the-wizard/slots/progressives/
In other states, there may or may not be such a rule.
Are odds changed after an idle time? They can be, practically. They can be legally, in NV.
https://gaming.nv.gov/modules/showdocument.aspx?documentid=1...
This is not a myth.