I don't have an ABXX-E. (
but opinions are like .... everyone has one...
)
The motion controller will take a time to boot, load its firmware initialise the ethernet connection, determine the interface connection speeds and setup it's IP address + send some initial packets back and forth to the device its communicating with.
I am not saying this will WILL work as I have no idea, but part of the setup is the two devices deciding on the network speed etc.....
It "may" help if you set the options on the PC to limit the negotiation choices between the devices to speed up the connection arrangement
Solutions 7 and 8 may help you in this post
https://windowsreport.com/fix-slow-lan-speed-pc/the others may help too.... (I have no idea, I normally turn my cabinet on first, then the PC so by the time its booted (fast boot from SSD) and I've logged on the devices are all happy with each other).
I'd suggest changing one at a time and see if it helps / improves things..... obviously if connections drop out or don't connect then you know what to unchange.... a good quality Ethernet cable may help too (after the network has been running a while you can have a look at the lost packets count which may tell you if the cable / connection is poor)
https://www.pcwdld.com/how-to-test-pack ... on-windows(sure there are other similar posts / walkthroughs for you to check out too).
Maybe give the motion controller a dummy file to run for an hour on repeat (add an M98 P L ) then check for lost packets, think the only thing you could to is change the ethernet cable to improve the number of lost packets. I expect its normal to loose some, but what an acceptable number is I have no idea. They will just be resent from the PC / motion controller to replace the ones with errors so no cnc motion will actually be lost. Increasing / decreasing the buffer can improve or worsen the situation.
Extract from the users manual (I've never fiddled with its default setting):
Communication buffer size: This parameter sets the length of the USB communication buffer. The parameter is in seconds. The shorter the buffer is the faster the machine will react to button presses. The minimum set value is 0.05seconds(50milliseconds) and the longest is 0.5seconds(500mseconds). Because the motion core of the software is running in a special high priority loop in our testings we found that 0.1seconds (100milliseconds) buffer length is enough in all cases and we recommend to leave this parameter at this value, but we left the ability to change this setting for the most flexibility of the software.
Note: suspect it will also apply to ethernet communication too..... given it too needs to go into a buffer to be sent and received.