In reviewing today's logs, I see that wired clients on the core switch have a number of log entries stating that they went offline and later online.  The interval between going offline and then online is anywhere between several minutes to roughly a half an hour.  This issue just started today.  The controller firmware was updated several days ago when it was released.

The issue is not affecting connectivity between downstream devices and the internet.

The gateway is an ER7406 v1.0 with firmware 1.2.3.

The switch is an SG2008 v4.20 with firmware 4.20.14.

It has been almost 17 days since the last switch reboot and perhaps a switch reboot may fix the issue but I would prefer to wait until I receive a response from Tp-Link.

Update 10-12-25:

This morning the log entries have dramatically increased and there are now 232 entries (4 devices = 58 occurrences).  The switch has 8 ports as follows:

1. ER7406

2. Downstream trunk to next switch

3. OC300

4. Printer (normally off)

5, VoIP Phone

6. iMac (normally off except when working)

7. NAS - Port 1

8. NAS - Port 2 (different subnet)

The 4 simultaneous entries mentioned are the OC300, the VoIP device, and the two NAS ports.  All are hardwired, on different subnets, and have fixed IP addresses.  The log has been exported if it may be helpful.  Another thing that I have noticed is that during the time the clients are shown offline in the logs, they no longer appear in the clients list.