There could be multiple reasons why simple operations taking so long for FEM Builder to complete. This symptom is typically encountered with large models -- and by large models we mean bigger that about 2 GB, but your mileage may vary. Sometimes if the operation is complex, it's just naturally going to take longer. A good example of this would be interpolating results, generating a contour plot, or saving a file.
However, when a simple operation takes an excessive amount of time to complete on a large model -- like creating a point -- the issue is almost always the undo feature. Undo was added to FEM Builder 4 in the 2019-02-06 version. For undo to work in FEM Builder, the state of the model is saved at each time it is modified. So for a large model, when a point is added, a snapshot of the entire model is saved prior to the creating a point. Then if the user presses Ctrl+Z, the model can be restored to it's previous state without the point. As more operations are done, more states are stored and the performance can quickly get bogged down -- even for moderately sized models.
Fortunately, the behavior of the undo function can be tailored to meet your needs from the Undo tab on the Tools -> Options dialog -- See figure below. The easiest way to restore performance is to uncheck the Auto save option in the Undo Controls group box. With auto-save turned off, undo becomes a manual operation, meaning that the model state is not saved as changes are made unless explicitly directly by the user. Other options on this dialog also effect the operations and performance of the undo function. The frequency of the state update can be decreased by increasing the number of changes per save. It is also faster to save to memory rather than a file.
Hopefully this will help you make the most of the undo feature in FEM Builder and provide the performance needed for a particular model or operation.