My feedback:

Building the maze takes too long. Maybe turn the play button into a fast-forward button when the maze is being built and solved.

The dark mode colors are pretty bad.

When you click and hold, it should turn every square the same color until you let go again. Right now it toggles every square you pass over, which is confusing.

When you move the start and end, it removes walls from the board.

Isn't Dijkstra the same as BFS?

Fast is not fast.

I think an inverted binary tree maze would be nice.