Hi @Fae! Thanks for you reply! I redid the tests, and did the ones you suggested too (reset everything, reinstall firmwares), and same results. I am sad that the test team failed to reproduce....

Hi @Fae, can you see the video?

Hi! @Fae Sorry, the video has more than 10MB, so I made a Google Drive Link: Link for Fae

Hi! @Fae First, sorry my bad English, tell me if you don't understanding something. I don't know what page show loop prevention, for me there was only the visual indication on the ports. Test 1: All...

@Fae Hi Fae! Sorry for the late reply. All the switchs are running the same firmware (Build 20181120) and same hardware version (V4). What error page do you mean?

I have 3 SG108E. The first switch is connected through ports 1 and 2 to the second switch. The second switch is connected through ports 7 and 8 to the third switch. I created LAG 1 on the first...