RTX 4090 sometimes gives no video via DisplayPort during boot

ATX with 12th13th Generation Intel® Core™ LGA1700 Socket Processors, TDP Max 125W, DDR5 DRAM, Multiple Display Ports Slot x 1, Mini PCIe x 1 + Micro SIM

slot, so I'm forced to use one of them with a Display Port adapter There the monitor gets some output at least, but only with

display port slot Audio jack · DisplayPortmini DisplayPort · DVI · Ethernet · HDMI · Kensington Lock Slot · SD Card Reader · MicroSD Card Reader

display slot 1m Panel Mount DisplayPort Cable, 4K x 2K Video, DisplayPort Extension Cable Male to Female, DP Extender Cord