@Riley_S Thanks for replying. Just to recap where I'm at with this and in response to your recommendations. I have been using the Kasa app but came across the Tapo app and tried that to see if that made any difference which it did not. So I'm back to using the Kasa app as I always have. The Kasa app successfully updated (4) HS100's and (2) KP400's fine and eventually (4) HS200's after multiple attempts. The problem seems to be with (4) EP10's I have. All are connected to the same network and responding fine both before and after the updates. When I try to perform the updates on the EP10's, the firmware downloads and appears to install properly as I get a status message that the update completed successfully and the Firmware Update tab under the Me (account) option clears and indiates everything is UP-TO-DATE. But when I go into the device info for each of the EP10's, the firmware still shows as being 1.0.2 not the current 1.0.5 that the Firmware Update screen showed would be 1.0.5 Build 221021 rel 183404. When I go back into Me, Firmware Update is again showing updates available for the 4 EP10's. It sort of looks like the EP10's are getting updated but their device info is not reflecting the new firmware version being in-place and thus the app keeps telling me an update is available.That's assuming that I can believe the updates completed properly consistent with the message indicating such. Anyway, I've also removed the 4 devices thus resetting them back to factory defaults and when I add them back in am prompted to update them which also indicates is successful but yet when I check their device info is still at 1.0.2 and the Me tab Firmware Update again shows an update to 1.0.5 being available. This again suggests something buggy with the firmware update app.For reference, the hardware version of them is 1.0. I've also just submittted an email support request so maybe they can shed some additional light on this. Thanks.

  @Riley_S Thank you for the follow-up. I checked Tapo and it too is showing Firmware Updates for the EP10 being available and the existing units still at 1.0.2. So Tapo agrees with the Kasa app. Not sure what you mean about changing dns servers as this is a home network on an Xfinity cable gateway using the provider default configuration which worked fine for all the other units and I wouldn't know what alterantive dns servers to use that wouldn't mess anything else up. All of the units including HS100's, HS200's, KP400's, and EP10's are on the same Wi-Fi and seem to have great signal and no problems operating otherwise. The EP10's are maybe within 20 feet of the router. In fact, the HS200's are the farthest from the router with the HS100's and KP400's next closest. The strange thing is that the Firmware Update indicates everything completed fine and reflects no issues until I go back in again and it shows the updates being available and the device info never reflects the new firmware.