Unable to add new key fob (2007 prius)

For context, I have two gen 2 priuses.

A while back, I bought an aftermarket SKS smart key fob for "Prius A" and was able to add it without issues by doing the "chicken dance". Recently, I bought another aftermarket smart key fob for "Prius B" thinking it would be the same simple process. However, no matter how many times I do the chicken dance, the car does not respond to the key. That includes dumb functionality. If I push the lock/unlock buttons, the red light blinks on the fob but nothing happens.

The add key procedure appears to progress normally, after inserting the fob 5 times and closing the door 6 times and then inserting the new key, the dash does blink for a minute and stops as expected. However, the key just doesn't work after concluding the process.

I assume this means there has already been 5 keys added previously? The car has had many previous owners. I found a post about deleting master keys, but the instructions were unclear and didn't appear to do anything. The instructions included a step where you "press the on button - lock 5 times", while the key is inserted. Does this mean pressing the lock button on the door 5 times when the car is on?

The instructions also didn't quite match the known good smart key programming instructions I used on Prius A, which involved pressing the power button 3 times before removing the old key, holding the lock and unlock buttons, and then similarly on the new key, followed by the lock button.

Are there more clear instructions on how to remove all non-master keys? (I assume that means removing all keys except the key being used to initiate the delete key function). If not, do I need to use techstream and are there instructions for adding and removing keys in that? (Of course, I'd need to know how to prevent accidentally removing the only good key I have). Is it possible to use techstream with the veepeak bluetooth dongle?

 

Update: It appears the car starts when the new key is inserted, but it cannot lock or unlock the doors using either the manual buttons or the smart key function. However, the red LED blinks when the door is opened or closed.

I deleted all non-master fobs by cycling the car on and off with the start button five times (pressing the start button a total of 15 times). After that, the car locked and unlocked five times. I then pressed a button on the old fob, which caused the car to lock and unlock five more times, confirming the other keys were removed.

Next, I went through the key addition process again. Everything seemed to work until I held the lock and unlock buttons on the new fob and then pressed the lock button. At that point, nothing happened. Just as before, the new key cannot lock or unlock the doors using either the buttons or the SKS functionality.

I’m not sure if the issue lies with the fob or the car. I did replace the battery as well. The two aftermarket FOBs I bought were from different sellers and appear somewhat different (the one that works with my old car has different shade of white for the lock/unlock icons and one key appears to be brass while the other appears to be steel. The seller did advertise it as a 3 button fob with smart functionality, but even if it didn't come with SKS it should still be able to use the lock and unlock buttons. Very odd.