GL-MT300N-v2 - Mobile phone connected in WIFI

Mobile phone connected in WIFI, client list in admin panel is detected as offline device.

I just tried mine, firmware 3.203 and iphone 11. It appear as online.

Can you check your phone’s wifi connection to see if you have used private address? Sometimes I use private address and my phone will be identified as a different phone, so may appear as offline. But this may not be your case.

I do think there may be bug and reported to developers

I updated to firmware 3.203, and the phones are connected in wi-fi, in the photo posted, a samsung S21 and a S10 but I see them both as offline devices.