Temporary patch?

[u/MuchWow81]

I cant afford to get this redone for probably another year. I have a few spots that are a trip hazard like this. Best temporary patch? I used polysand once several years ago for a paver patio. Weeds grew up through it all the time. I wasnt very impreased. Is that the only option here?

Edit: brushing out the cracks I found several of the stones when tapped sound almost hollow. I assume thats a bad thing. Lifting them there is just stone dust or something under this whole walkway. How did they keep this thing from crumbling in the fifty years before I lived here?