Questions about Philips TAW6205/10

I have four of these speakers and would like to pair them to provide sound in a larger room. I managed once to get each of the speakers into the WLAN according to the instructions with the IOS app "Philips Sound". Now the app stops with the message "Update 1 of 2 is being completed" and after a long time I get a message "Devices not found - Some of the recently updated Play-Fi devices were not found". The network is OK, distances under 9 metres and line of sight to the antenna. Does anyone know about these things and can give me a hint? They were all once in the WLAN and were individually selectable as output devices. But when I switched to the next speaker, they were removed from the list. How do you pair these things?

I have connected my two speakers to my Philips soundbar. Until recently, the LED bar of the two speakers switched off together with the TV and the soundbar, which is great. But for the last two days, the LED bar has been switching itself on again all the time, even though the soundbar and the TV are switched off. What could be the reason for this?

Incorrect specification: This is a mono speaker --> 1 audio channel, not 2 as incorrectly stated. To get stereo sound, you have to buy two of these speakers.

Do these speakers work with the Fidelio B97 and Philips OLED+936 TV with DTS Play-Fi?

Does anyone know how to activate the voice assistant on this stupid thing? I've been on it for almost 3 hours and I feel dumber than a monkey!