I have so many pairs of Sole Bliss sneakers! I had the same problem of struggling to close up the zipper until I realised you're supposed to adjust the laces the first time you wear them...
With my first pair I called them to complain about the zipper and they told me that when you first try them on you need to loosen the laces first, put your foot in, then tighten them to however is comfortable. Then after that you just use the zipper to take them on and off and don't have to touch the laces!
They could make it a little clearer that this is what you're supposed to do though I think as it's not that obvious. Anyway I've taken their advice with every pair I've bought since and the zippers have been completely fine! And the sneakers are so pretty and comfortable... on the more expensive side but so worth it for my bunions.