@Wayne-TP Yes, that was the point, now they are in the same room (2 valves, temp sensor and the hub). Btw, valve and temp sensor MUST be on the same hub in order to set it as a designated sensor. I have checked just now, and the issue is still there, you can see one TRV has the correct reading (ok, 0.1 off due to readout delay), but the other one is back on its internal sensor.... (it will get back to external after a while, or I have to make a switch internal / external and it will read right away). 

I have also tried the night mode and it makes things even worse:

(these are brand new TRVs and hub - I have moved the old ones to another building).

Its like they only have rough thresholds 0-25-50-75-100% open.  They open to 50%, make one correction to 25%, still too much and back to 0. 

And they cycle like this endlessly :(

  @Maciej54 

You may be interested in this thread as we have also experienced a difference in temp reading between sensors and trvs. https://community.tp-link.com/en/smart-home/forum/topic/848416

@Daz183 thanks for the info! Well, it might be how you describe it! In my case it happens at random times, and whats interesting it quite often affects only one TRV in the group. 

I have checked just now, and one TRV is showing 22.2 the other 22.4 and the external sensor shows 21.8! 

  @Wayne-TP I did fill in the in app form - Helo -> Contact us. When submitted, I did not get any email confirmation or a case number so I have no idea if reached anyone. 

SteveWex wrote

  @Maciej54 

 

Came across this thread and have to say; we're probably not complaining about it because this isn't happening to us?

 

My KE100 heat gradually. I can hear them making adjustments as the room warms up. Once warm, they maintain well.

 

Perhaps you have a bad batch (assuming you have reset to factory and reinstalled. Maybe they're just not suitable for your specific radiator valve, or perhaps the valves are jammed (they have a finite life and I've needed to replace a couple of mine at 6 years old).

 

As for Tado, I've been there, and thankfully even after 7 months after explaining the reasons to Amazon, they allowed me to return the lot for a refund, they are far worse than KASA. I've ended up with a combination of Hive Thermostats and KASA TRVs and touch wood it's working well and maintaining the temperatures consistently.

  @SteveWex I have multiple locations with these TRVs, and they all behave similarly. Here is another graph, from another building, that has totally different characteristics. That is, bigger, older radiators, and a big room that is hard to get warmed up, so it has huge inertia, diferent make/model of the valves. The result: same oscillation but different amplitude. So even here the valves can't stabilize at a given temperature. Yes, the temperature is somewhere around what was set, but the cycling and cooldowns are rather annoying. 

The range here is heat up to 19.2°C, cool down to 18.4°C, heat back to 19.2°C, cool down again... In my view, the valve closes a bit, waits TOO SHORT, closes a bit more, and keeps doing this. As the temperature falls, it does the same thing in reverse on the way up. It should either have longer wait times between adjustments, or learn and adapt to the room's thermal inertia. In a room with more powerful radiators, you'll just get a smaller zigzag pattern. But it never stabilizes the way every other TRV I've used does (both analog and smart ones).

  @Wayne-TP thanks a lot! I really appreciate that! I have already followed up on this providing all required information like MAC addresses.

Lets hope we can solve this!