I have noticed this inconsistency in Photoshop since version 2020. Try this please:
1.- If we add a GRADIENT FILL LAYER. Among other things we can change the location of the gradient by clicking and dragging on the canvas. 2.- But if we enter the gradient editor (although we don't edit anything), we can no longer move the location of the gradient. 3.- The simplest way I have found to solve it (on Mac) is to change the application momentarily (Cmd + tab and again Cmd + tab); this unlocks the function, and we can move the gradient again with the mouse. (Other annoying "solution" would be click Ok in the Gradient Fill box dialog and double click the thumbnail of the layer but... no).
I would appreciate if Adobe takes action in this particular issue that we have been dragging at least since PS 2020