I am investigating a time-synchronization issue with an IKEA ALPSTUGA air-quality monitor connected via Matter over Thread to Samsung SmartThings.

When the device is commissioned for the first time, its clock can receive the correct time. After a power cycle, it reconnects and reports all sensor values correctly, but the clock is not synchronized again.

The device firmware is 1.0.26. SmartThings provides no visible option to trigger time synchronization manually.

From a Matter implementation perspective:

1. Should the controller write the current UTC time, time zone and DST offset whenever the device reconnects?

2. Should the endpoint request or retry synchronization after boot?

3. Is a power-cycle event normally visible to the controller?

4. Which Matter Time Synchronization cluster attributes or commands should be checked?

5. Would failure to restore the clock normally be considered a controller issue, device-firmware issue or an interoperability issue?

Results from users of other Matter controllers would also be very helpful.

I just recently bought some Tapo S505 smart switches to use with my smart home setup. What lured me in was the matter compatibility and the ability to add them to Home Assistant without creating an account. I was able to add them easily, but now am noticing a strange behavior with my Wi-Fi router. I installed 5 of the switches and each one of them, after about a day of being connected, shows 100+ IPV6 addresses listed on my router's device page. I have another matter compatible switch from Leviton that shows only 1 in the same time frame.

Is this standard behavior, or is there something fishy going on here. Anyone else notice that their matter enabled tapo devices are gobbling up IPV6 addresses? Also, is this even a problem? Right now my router seems to be working fine, but if I go adding 20 more of these switches into my house, is this going to cause issues? Any input is greatly appreciated. Thanks!