RaspberryPi 4/5 Ethercat Rtelligent ECT60 Synchronization error

I have an issue, after running LinuxCNC Raspberry Pi Ethercat with  Rtelligent ECT60 closed loop stepper controller i will gat about roughly half of hour or sometimes less  EtherCAT ERROR 0-0: AL status message 0x001A: "Synchronization error".  I have narrowed down problem that it occurs when raspberry pi ethernet goes down for a moment and then back up.[ 4189.236501] EtherCAT ERROR 0-1: Failed to receive AL state datagram: Datagram timed out.
[ 4189.300500] EtherCAT 0: 0 slave(s) responding on main device. Re-scanning on next possibility.
[ 4189.300504] EtherCAT 0: Re-scanning now.
[ 4189.848960] macb 1f00100000.ethernet eth0: Link is Down
[ 4189.849054] EtherCAT 0: Link state of ecm0 changed to DOWN.
[ 4190.184505] EtherCAT WARNING 0: 50 datagrams TIMED OUT!
[ 4191.898355] macb 1f00100000.ethernet eth0: Link is Up - 100Mbps/Full - flow control off
[ 4191.899068] EtherCAT 0: Link state of ecm0 changed to UP.

Then the narrowing down part, I have tried with Raspberry Pi5 and couple of Raspberry Pi 4, I have used own build Rt-preempt kernel and all Linuxcnc/Ethercat from sources and now I have downloaded ready made LinuxCNC 2.9.4 Raspberry Pi image for rpi4 and rpi5. I have followed installation instructions from "Ethercat installation from repositories - how to step by step". I have tried with two separate controller boxes that are having Rtelligent ECT60 boards with two CNC machines and test configuration with just raspberry pi, controller and stepper motors. I have used multiple brand new ethernet cables, tried multiple Raspberry Pi power supplies including original one.  I have tried to disable all other possible services like ntpd NetworknaMager touching interface. I can say that I have changed every component in system. Ethercat is direct cable connection from Raspberry Pi to ETC60.

Good ideas what to try next or even workaround ideas.  When searching "macb 1f00100000.ethernet eth0: Link is Down" for rpi5 or similar for rpi4 i got lot of matching posts from raspberry pi forums. Just not help, there is similar theories about reason, bad ethernet cable, bad power supply, bad ethernet switch. I have tried with multiple cables , mutiple power supplies and I don't have switch but direct ethercat.

I least assume that issue is not in Ethercat configuration or Rpi RT-Preempt kernel because all of these are now standard from repo.