How can I improve the adhesion of my rubber sealant on my walkway in the Pacific Northwest before winter arrives?

We get quite a bit of rain here in the Pacific Northwest. A few years ago, I noticed some cracks in the walkway, so I used some Quikrete Polyurethane Self-Levelling Sealant to patch them up. It worked really well and held up through a couple of harsh winters. However, the sealant is starting to peel now and I want to fix it before winter comes.

I think the issue might be that I power washed the walkway, filled in the cracks with small aggregate, and then applied the sealant. It’s a bit runny, so if there were any gaps or dips, I would add more until it was level. Unfortunately, the sealant is peeling away due to debris and sand blowing down the side of the house.

Do you think I should fill in the cracks with something else to level it out? Maybe use backer rod or etch the concrete for better adhesion? Or should I switch to using actual concrete repair instead of the rubber sealant?

Also, the gutter is causing some damage by wearing away at the surface and creating a sandy area.

Any advice would be appreciated!