Since OpenWrt switched to APK, previous guidance using opkg should not work. This procedure disables Wi-Fi so attempt this only with a wired connection to your router. Wi-Fi is re-enabled at the end. This was done on an OpenWrt One router with 25.12.0 OpenWrt version.
Wired router connection
Open browser, enter router IP address, and login to Luci
Go to System > Software
Click Update lists… and Dismiss the popup
Click Installed tab
In Filter type wpad
Remove wpad-basic and Remove wpad-basic-mbedtls
Click Available tab.
Install wpad (nothing after “wpad”)
Go to System > Reboot and click Perform Reboot
When system comes back up, log into Luci
Go to Network > Wireless
Choose the SSID where you want WPS enabled and click Edit
Scroll down to Interface Configuration and click the Wireless Security tab.
Scroll down further and at the bottom is now an Enable WPS pushbutton box. Check the box and click Save then Save & Apply.
Re-enable Wi-Fi network(s). You may need to Edit, Disable, Enable.
If you have a recent backup (you create these every time you piddle) you can go back, sysupgrade and remove, anything. e.g. what you tried to pull from a working install.
It's why someone put the effort into those little check boxes.
I do not know what you have done; restored and tried the same removal method?
I'm not going to rant about WPS; you should just know better. Print a QRC better. Use NFC better.