Game really doesn't like alt tabbing or changing out of full screen.

[ForteDS]

When I alt tab out, I'm unable to alt tab back in, and now that I'm trying to get it into window mode to avoid that issue, the game just crashes.

[USARice]

Same here

[Smetz]

For what it's worth, I had no trouble putting it in windowed mode. When you alt tab it automatically freezes the game wherever you are.

[USARice]

I went into the gaming .ini and set it to borderless windowed mode. Issue is gone for me now. Ini is located in the game folder itself in steamapps.

[🪻🧋Sylvie💮🍃]

Same here. For some reason, after I press Alt+Tab, I cannot get back in-game and apparently all I hear is in-game audio but cannot see anything on screen. Thus, I have to press Alt + F4 to close the game. Then finally, I have to relaunch SonicMania.exe via Steam Client.
https://www.youtube.com/watch?v=iQLI2WgtIc8

[Queen Ishtar]

Bump. Also having this issue.