Wall plugs failed to hold up curtain rod. Need advice on how to fix gaping holes in my wall

I put up some curtains in the room which failed in ~48 hours.

Solid masonry wall - I went and bought wall plugs from bunnings, which said to use a 8mm drill. Measured them up, drilled and hung up the curtains.

2 days later, my wall now looks like this: https://imgur.com/a/lZbMZjV

So I have questions:

1. Why did this fail? Looking at it now, I think the screws were too short for the plugs?
2. How can I repair this? I still need to put up curtains and will need to drill back the same area (or spots next to it). If I get some type of putty/polyfilla, fill all the holes - will it be strong enough to drill again?

Any advice would be appreciated.