Boss BR 80 with a startup problem

I have a Boss BR 80 8-track recorder with a problem. A microrecorder to be precise. This device has an on/off button, which is of course intended to start the recorder as soon as you press the button for a while. However, the button has a few other functions, such as switching between MTR mode, E-band mode and Live rec mode with a short press each time. The problem I have now with this recorder: when I press the power button and still hold it down, the thing starts up, but everything stops as soon as I release the button. I would like to ask if you know why this happened? And could this be something that can be repaired?
Hopefully you can comment on this?