You have probably pushed her out of the top, and the top-opening enclosure is the mechanism. Regals and bolds build silk retreats up high, usually in a corner near the lid, which is precisely where your hand goes every time. Destroy it enough times and a spider stops building there.
So she may simply have relocated to somewhere you do not reach. That is not burrowing in the species sense, it is a spider choosing the one spot you leave alone.