Need help understanding why spymaster didn't level

Upgrade by sacrificing the Spymaster is limited to only one time. That’s it.

I'm trying to build my first temple. It basically looked like the image except there used to be a level 1 spymaster where it says "L1 spy". I ran the temple going up the left side chain first until I got to the L2 spymaster at the end, and then I ran through the center section. The L1 spymaster room was empty. Then when I left the temple, I locked the L2 spymaster at the end of my chain, expecting it to level up to L3 since it "killed" the L1 spymaster. The L1 spymaster was removed as expected, but the L2 spymaster didn't level up. What did I do wrong?

Thanks!

My knowledge are kinda limited , but I always thought killing each other only level once Another level are from medallion.

If I understand you correctly you need to run the temple first and then lock the room before you close the temple. Don’t lock the last spymaster before the run.

you should have locked the lvl 2 spy master b4 entering the temple
because of the order you did it the lvl 2 spy master was killed aswell as the lvl 1

Was the lvl 3 spy lvl 3 before?

I do not recommend using spy masters outside of your actual chain to push levels. If you cannot use it in your main chain, don’t use it.

You are more likely to get spy masters when you need them to level up another spy master. Just let it be missed if you are not ready for it in your chain! You can use a free tier up if needed, build stuff as fodder in your fake rooms for more oppurtunity. Golem/t2 commanders/syn flesh labs?

Also always lock after your run when solo, much better habit to be as locking before will stop a spy master from trying to assassinate it.

From my experience, you can’t lock the spymaster first. If you run the temple before locking it, the new spymaster you place should be dead when you enter and the other one will level up. Just make sure you lock it after the run.

Because they’re not technically part of the same chain. Building up from the middle is a separate chain. If your other spymaster was opposite the corruption chamber on the right it would have worked.