Hello, I have several TL-SG108E and TL-SG108PE switches that have been configured to work with Ubiquiti switches and VLANs. I will post the configuration steps below. Everything has been working great until yesterday at 1630. At 1630 all my TP-Link switches stopped responding to Ping. I use PRTG to monitor my network and received email alerts for each switch that it stopped responding to Ping. I tried to ping them from my computer and there is no response. I also cannot access the web interface for the switches. They are still passing traffic as they should. I can ping printers, cameras, PCs, etc. that are connected to the switches. I pulled a spare off the shelf that was already configured and it did the same thing. I factory reset it and was able to get into the GUI. I updated the firmware to the newest version from TP-Link's website and went through the same configuration steps that worked before, but once I change the profile that the Ubiquiti switch uses from my MGMT VLAN, it stops responding to ping. I set the port back to the MGMT VLAN and it came back up.  I then continued the rest of my configuration and then switched the profile back to what it needs to be for those VLANs and it stops responding to Ping again.  Now switching back to the MGMT VLAN the switch no longer responds to Ping. However, when the port is set to the profile I need for those VLANs, those ports on the TP-Link switch pass traffic as they should. Any ideas what is going on? I would like to be able to monitor these switches with PRTG as well as have the ability to login to the GUI to make changes without having to factory reset the switches. Any ideas?

Configuration steps (I modified the steps in this article to get the VLANs to work correctly in the beginning (https://community.tp-link.com/en/business/forum/topic/105250)):

1. Set the port to VLAN 50 (MGMT) in UniFi.
   
   
2. Scan the MGMT DHCP Range for the Switch.
3. Login to the TP Link switch as admin/admin.
4. Set the new Password (6-16 characters, English letters, digits, and underlines).
5. Go to System > IP Setting > DHCP Setting > Disable.
   1. Enter The Following:
      1. Static IP Address
      2. Subnet Mask
      3. Default Gateway
   2. Click Apply
6. Go to VLAN > 802.1Q VLAN
   1. Tick Enable by 802.1Q VLAN Configuration, click Apply, then click OK.
      
   2. Enter VLAN ID “50”, VLAN Name “MGMT”, Tag the UPLINK port and click Add/Modify.
      
   3. Set the port profile to TP-Link Switches in UniFi.
      
      
       
   4. Enter VLAN ID “1”, VLAN Name “Uplink”, and click Add/Modify.
      
   5. Create VLAN ID “3”, VLAN Name “CorpWired”, and assign ports 2-4 as Untagged. Create VLAN ID “7”, VLAN Name “Printers”, and assign ports 5-8 as Untagged.
      
7. Go to VLAN > 802.1Q PVID Setting. Assign PVID “3” to ports 2-4 and PVID “7” to ports 5-8.
   Note: This must be done in order to remove them from the default/uplink VLAN in the next step.
   
8. Go to VLAN > 802.1Q VLAN.  Assign port 1 as a tagged member of VLANs 3 and 7.
   
9. Remove ports 2-8 as members of VLAN 1 (check “Not Member”).  Leave port 1 Untagged in VLAN 1 to not get disconnected from the switch.
   
10. Ports 2-4 are now members of VLAN 3 CorpWired, Untagged Ethernet frames will be assigned to VLAN 3 due to the PVID setting and are being forwarded to port 1 only.  Ports 5-8 are members of VLAN 7 Printers, Untagged Ethernet frames will be assigned to VLAN 7 and are being forwarded to port 1, too.  Port 1 is a Trunk port, Tagged frames will be forwarded to members of the appropriate VLAN (VLAN 3 > ports 2-4, VLAN 7 > ports 5-8, Untagged frames > port 1.