One those 100Ks might have been open. When you unsoldered them you "fixed" them. This will not be permanent.

That was a problem sometimes, I learned to just use circuit values. Unless it is tube stuff you you cannot even check them in circuit, and you heat the leads to take them out of circuit and many of the "heal up" all the sudden, which can lead you down the garden path.

Been there done that. I would change them, what are we taking here ten cents ? That vs customer satisfaction is easy to figure out. Any circuit with even those slightly ambiguous results, change the high value resistors.