GitHub is currently merging PRs in the UI with the wrong merge method

I thought I was going crazy before finding this bug. Hit this a few times this evening, very annoying.

Is this code written by GitHub employees? No wonder why so many down time with GitHub. Countless inconsistencies in this small piece of code

This doesn't affect me but I am curious if it's possible to download the PR and use local tools for the desired merge?

I tried to shoot myself in the foot but Github broke the gun and it hit a firing range target instead, how did this reach production?