Cisco SG350XG - LACP Trunk Port Added/Removed Continually

[thehappyadmin]

We have two unstacked switches connected via 2x 10G links setup with LACP on each switch identically (models and firmware below).

We are observing constant "flapping" (not physical, but port removed/added to LAG group) on only one of the two aggregated links on each switch (see logs below).

We are also seeing Receive Errors on only the 12 port switch (with the newer firmware), suggesting that the 24 port switch with older firmware may be sending bad packets.  The 24 port switch does not have any receive packet errors. (see attached image)

Hardware / Firmware

SG350XG-2F10 / 2.5.7.85 (12 port, newer firmware)

SG350XG-24T / 2.5.0.92 (24 port, older firmware)

Logs Example

On either switch, it's only the first of the two ports setup with LACP that is removed/added.  The second port in the group on each switch appears 100% stable.  We haven't tried a new cable yet.

2147441574	2021-Apr-13 15:20:37	Warning	%TRUNK-W-PORTREMOVED: Port te1/0/7 removed from Po1   
2147441576	2021-Apr-13 15:19:06	Informational	%TRUNK-I-PORTADDED: Port te1/0/7 added to Po1   
2147441577	2021-Apr-13 15:15:49	Warning	%TRUNK-W-PORTREMOVED: Port te1/0/7 removed from Po1   
2147441578	2021-Apr-13 15:13:18	Informational	%TRUNK-I-PORTADDED: Port te1/0/7 added to Po1   
2147441579	2021-Apr-13 15:09:37	Warning	%TRUNK-W-PORTREMOVED: Port te1/0/7 removed from Po1   
2147441580	2021-Apr-13 15:08:06	Informational	%TRUNK-I-PORTADDED: Port te1/0/7 added to Po1   

Okay, the two obvious things to try are:

1. Try a new cable (although, the issue we see doesn't seem to be physical)
2. Upgrade firmware on the 24 port switch

I didn't see mention of this specific fix in the release notes so not sure an upgrade will resolve anything:

https://www.cisco.com/c/dam/en/us/td/docs/switches/lan/csbms/350xg/rn/b_tesla-release-2_5_7.pdf

Does anyone have thoughts or suggestions?

EDIT: we started noticing this issue two days ago only, and the switches have been setup with LACP and untouched for about 3 weeks prior.  No LACP before that time.

[thehappyadmin]

I may have solved the issue (or at least caused to stop, for now).  I noticed that EEE/Green Ethernet is/was enabled, though we don't really need that.  (Perhaps I have other things enabled which could be disabled as well)

I disabled EEE on the 12 port switch and it's been > 10 minutes without seeing the issue either in the log on either switch AND the receive errors on the 12 port switch seem to have stopped.  Normally it was at most 4 minutes before the issue showed up.

Note that all of the active ports did drop for about 10-15 seconds on the 12 port switch when I disabled EEE.  So perhaps either this action or disabling EEE altogether seems to have resolved my issue.

I'll return to this post if the issue returns.

[thehappyadmin]

The problem hasn't returned so far.  Fingers crossed.  If the issue DOES come back, I'll see what other things I can disable on the LACP ports and then possibly update the firmware on the 24 port switch.