The problem is on evpn-vxlan and the passage of DHCP packets from the QFX5100 leaves (dhcp works as usual, one of 5-7 attempts successful), the identical configuration on the QFX5120 works without any glitches or delays. Static IPs have no problem.
Are there any differences between the configurations of Laeaf QFX5100 vs. QFX5120 for evpn?
QFX5100 and QFX5120 are leafs spine is MS204 with dhcp relay.