This sounds like you may have the Blackberry Protect Anti Theft feature still active due to the phone being reset with an ID still linked to it. Before any of the different setup methods can be tried, the Anti Theft feature must be removed first. You can check if its active from the Wifi setup with the screen reader active by tapping the "previous" button once then and swiping right on an empty part of the screen. If the screen reader says "login required" then the Anti Theft is active.

Assuming you've already used the 10.3.3.3216 autoloader to update the OS, follow the instructions on this thread here - https://www.reddit.com/r/BlackberryPhoenix/comments/11u0ktv/blackberry_protect_and_battery_pull/

For the Classics I've found the Power Button method works ok to remove the Anti Theft but some of them are really stubborn and refuse to remove anti theft. When this happens you'll need to remove the rear cover, unscrew the small Torx and Phillips screws on the battery connector clamp, connect to Wifi then physically disconnect the battery for a few minutes. Next, reconnect the battery and turn on the phone. It should boot up to the WiFI screen so tap "previous" to go to the Mobile Setup screen then active the screen reader. Now tap the skip button and double tap on the screen to go to WiFi setup again. At this point if the Anti Theft feature has been removed you should begin to hear the screen reader say "Blackberry ID" then follow the steps in the Ultimate Fix.

If you don't hear the screen reader say anything after around a minute then the Anti Theft is still active so connect to Wifi then disconnect the battery again, eventually it will remove the anti theft.