I believe that's the standard message when you go into Download Mode on a Samsung device when booting up. If you hold down the volume up and power keys on boot up you get into recovery mode.
That's the Download Mode or OS install mode. When you're about to install a custom ROM or flash an update via external software (e.g. something called Odin), you go into that mode.
Basically, if you want to turn on your phone, just press the power key only, To get into recovery mode, it's bixby+volume up+power, and for download mode it's bixby+volume down+power.
I'm also assuming you used an OEM screen. If not, that may be the problem but it's less likely.