What kind of sock/filter do you use for cryo hops in the keg? They're pretty fine!
You might want to try a few different options. Hops is such a difficult thing to filter well.
Inevitably the issue with filtering hops is that if the filter media is too fine it will block the filter almost by definition. If you completely block the filter then you sacrifice extraction. On the other hand if you have a filter that is a bit larger in the pore size then you get particulates getting through the filter. So the perfect filter is really a comprimise of these two factors and what level of comprimise you are willing to accept defines the pefect level of filtration. Ideally some type of multi level filtration would be best but no such hop filter exist for dry hopping kegs as far as I am aware.
I really prefer using these:
https://www.kegland.com.au/hop-sock-small-grain-bag-biab-944.html
I use them once or twice then just throw them out. If you want a reusable optoin this is probably the best:
https://www.kegland.com.au/stainless-steel-hop-tube.html
We did also stock these at one stage:
https://www.kegland.com.au/new-high-grade-hop-sock-small-grain-bag-biab.html
These had a very fine mesh but the bag was not strong and it could come apart on the seam line too easily so I think the ones above are better.