@BJ_Kim, do you have your M1T and Chromecast devices set to Exclusive mode from within Roon under their Zone Settings or Settings → Audio → Device Setup? If so, then your computer you are using for your Core may not be releasing the device.
What computer (type and OS) are you using for your Core, and if you disable in Roon the device you want to use directly with Tidal, does your Tidal app see the device?
Thanks for taking the time to write in! Sorry for the delay in getting to your thread.
Following up on @Robert_F’s comment, it may be worth double-checking to confirm that Exclusive mode is disabled across each separate zone?
If possible, could you please reproduce the issue, and share the specific date and time in which the issue occurs? From there, we’ll pull diagnostics on your core device and should be able to take a closer look.