Polk Omni A1- How to reset the amplifier to factory settings?

Hello,
I have problem with WiFi connection, possibly due to an incomplete update via the DTS Play-Fi app.
Everything was beautiful until today ...
I tried to run Tidal in the Polk application. But it was showing a message that it cannot connect to Tidal. While there was no problem with login to Tidal app itself.
So I decide to reinstall Polk app on my Redmi Note 9 Pro (Android version: 11 RKQ1.200826.002). What was my surprise when I did not find the Polk application in the google store (after deinstalation).
In that case I decided to install Play-Fi app.
When I was run it, some update files just started do download..
So I was wait till end, but some kind of a problem appeard and stopped process.

From this moment my Polk Omni A1 behave diferent than in past.
When I swith on optical input, it turns off by itself after fiew seconds.
While it is on (orange TV indicator is on) it play music (I have Polk T50 connect with this amplifier) but it turns off after less than 1 min.

Also it react different to Wi-Fi Setup Button. Right now if I plug in power cable and press and hold WiFi setup button (3 sec and more), the led indicator is not blinking and there is no specific two tones from speakers.
If I switch optical In and then hold Wi-Fi Setup Button then after about 10sec (maybe a bit more) appear tones but differnt than in past.

So please tell me if it possible to fix it by some factory reset (if possible)?
Or maybe by manual update via USB? If yes, pleas tell me if it is the right zip file: https://dtslisten.app.box.com/v/Play-Fi-Update
Any hints for carrying out this process?

Thank you in advance for your help.
Adam

Answers