Linear optimization - Excel Solver



I’ve been teaching Linear Optimization using Excel Solver for about a year. I found that Excel Solver is occasionally not consistent in terms of solution. For instance, with the same question and model (and constraints), if I run the model, it may give 2-3 solutions (though the optimal value is THE SAME). My students also experienced the same issue in the final exam that I gave them so I’m still reviewing this issue now.
I Googled and found that this is down to the algorithim:
Can any experts here explain better than the link above?
Tks so much in advance.