When the pager_navigation function does not create the correct link…
If you have used a route name in the call to this function, it will be parsed based on your routing.yml file, this means that if you don’t have a :page variable listed (and you probably don’t) the route will ignore the page argument that the pager function tries to add.
The easy solution is to add /* to the end of your routing rule, so that any other parameters are allowed.
E.g.
myroute:
url: /somewhere/:userid/*
param: { module: myModule, action: myAction }
mynextroute:
url: etcNow your routing functions will add any extra parameters as necessary.