OpenShift Container Platform 4 Master Nodes not always getting the same IP after restart when using dhcpd

Issue

• Our OpenShift Container Platform 4 Master Nodes running Red Hat CoreOS are regularly getting a new IP assigned by the DHCP server (dhcpd).

• The lease file of the DHCP server shows the same MAC address but a different "UID" for each entry:

  $ cat /var/lib/dhcpd/dhcpd.leases
  [..]
  lease 10.228.108.221 {
    starts 5 2020/10/30 14:42:33;
    ends 5 2020/10/30 14:52:33;
    tstp 5 2020/10/30 14:52:33;
    cltt 5 2020/10/30 14:42:33;
    binding state free;
    hardware ethernet 00:50:56:ab:bd:ef;
    uid "\377V\224\275\270\000\004/Q\343\243\025<E\026\211\244\022`\261Y4)";
  }
  lease 10.228.108.226 {
    starts 1 2021/01/11 14:30:37;
    ends 1 2021/01/11 14:40:37;
    tstp 1 2021/01/11 14:40:37;
    cltt 1 2021/01/11 14:30:37;
    binding state free;
    hardware ethernet 00:50:56:ab:bd:ef;
    uid "\001\000PV\224\275\270";
  }