Transition in beforeModel with query-params sets query-param with same name on different route

Here's an ember twiddle that reproduces the issue.

https://ember-twiddle.com/13b16b6085b367db5cc921da78426312?openFiles=routes.foo.js%2C

If you click on the link to go to Foo then to Bar and then back to Foo you'll see that the url behaves as you would expect. /foo?param=true > /bar > /foo?param=true

However, after a refresh, if you click on Bar first and then Foo you'll notice that the param gets stuck when you go back to Bar. /bar > /foo?param=true > /bar?param=true

I did read about sticky params and I'm not sure whether the intended behavior is that the param sticks all the time or if the issue here is that it should not be sticking in this situation at all but the inconsistency seemed to point to something being up.