There is, but for some reason it still cycles through all inputs where it can't immediately sync and lock onto the manually selected input. Under HDMI everything is fine, but being an older 4k monitor only 4k/30 is possible.is there not an option in the monitor to stop the cycling? that would be annoying... might try asking the oem like nobu just suggested.
Sounds like that monitor isn't listening for the wake-up signal on the displayport input. Bummer. I'd send the manufacturer a message, maybe they'd update the firmware if it's not a hardware fault. Apparently it's common, though.
Meh, it's been like this for so long I'm sorta used to it now.