Sonoff 4CH Pro Rev2 WiFi - difficulty pairing with eWeLink, WiFi LED cyclically on

Hello, I have purchased a used Sonoff 4CH Pro Rev2 and I am having trouble pairing it with the eWeLink app. After connecting the power supply, the first 3 diodes: R1, R2, R3 light up orange and the diode at the very bottom (WiFi sign) flashes blue for a while and then every now and then just lights up blue for a while and so on and so forth. When the button is held down for 7s nothing happens. Maybe one of you has had this problem? Thank you in advance for your help!
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Maybe the previous owner had uploaded different software.

sk1977 wrote:

Maybe the previous owner uploaded different software.

well that's where the problem comes in, the offer said new - only checked product performance. Tomorrow I return it and order a completely new one, this sonoff I have saved on the auction even for a cool price, but cuz I will wait until tomorrow maybe someone else will come up with something .

Pairing as per instructions?
Phone used for pairing connected to WiFi 2.4?

sk1977 wrote:

Pairing as per instructions?
phone used for pairing connected to WiFi 2.4?

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Exactly yes, in the topic I posted a link to a youtube video of how I do it, I hold down any button for 7 seconds and it should flash but nothing happens. When I click on the r1,r2 or r3 button (that is the sections that are on) nothing happens, once power is applied they automatically turn on.