No, it means you've accidentally set it to run in 25hz lift by default, and it remembers you "want" that setting. I can't remember off hand how to set it backto run "flat" by default, but I can look later if you don't have the manual to hand.
4.2. Lifting EQ
The LIFT button switches between the EQ settings of Anti-Mode 8033. The settings are stored with a longer press of the LIFT button. A brief sound heard from the subwoofer after settings have been stored indicates that you should release the LIFT button.