I'm running Ubuntu Studio 19.10 on a 2010 MacPro desktop 2.4 GHz, 8 core. I connected a Dell U2717D monitor to the computer, through both the mini display port and the dvi port. With the mini display port, I only saw the message that no signal was detected through the connector. With the dvi port, the monitor does work, but only after switching from an Acer monitor; if I logged out, I lost the signal. I don't think that Ubuntu Studio is the problem, since I am running the same version on a Dell laptop, and the laptop successfully connect to the monitor. Does anyone have a solution to this, or a suggestion as to how to remedy it?

Thanks.