No longer able to join Wi-Fi network

I have four Shelly H&T's that I did a recent firmware upgrade to 1.9.0 on and now they no longer connect to my Wi-Fi network.

I can reset them and get to the initial menu at the address of 192.168.33.1 but the joining the client network functionality no longer works.

I visited the firmware archive at:

https://shelly-forum.com/index.php?shelly-firmware-archive/

I have tried the downgrade procedure to the 1.8.0 and when I paste in the URL to the browser (chrome).

http://192.168.33.1/ota?url=http:/…HHT-1_build.zip

I get the following display:

{"status":"updating","has_update":false,"new_version":"","old_version":"20201124-091711/v1.9.0@57ac4ad8"}

However the the H&T blinks for a while and then stops blinking and never does the downgrade operation.

What is the correct procedure that I should use?

What is the procedure to use with a downloaded version of firmware?

Ok I was finally able to step back 1.8.0 and restore my WI-FI connectivity. Steps that I had to take:

1. Connect my windows laptop up to wired Ethernet connection.

2. Share my laptop as a mobile hotspot.

3. Record the shared mobile hotspot (after removing the space in SSID designation) information.

4. Turn off the mobile hotspot sharing

5. Hard reset the H&T

6. Connect to it and ask it to join the shared mobile hotspot.

7. Do an IPCONFIG on the laptop to find the IP address which in my case was 192.168.137.1

8. Soft Reset the H&T it will blink and then stop blinking when it connects.

9. Scan the subnet in step 7 to find the H&T IP address

10. Connect to the new IP address to verify that it is online.

11. Visit the firmware archive page and select the version that you want. The page will give you an URL to execute.

12. Soft Reset the H&T it will blink and then stop blinking when it connects.

13. Immediately execute the URL for the update.

14. The LED will start blinking, wait for it go out.

15. Soft Reset the H&T and connect to it's IP address. Verify that the firmware has been downgraded. In my case it took two tries.