Stubbs munch stations

[Mouse19]

So I have purchased 3 of these second hand from Facebook marketplace having had them on a livery yard I had my old mare at a few years ago. The livery yard swore by them and had 30 odd horses using them with no issue.
The problem is that none of my 3 horses seem to like them. I feed hay and it doesn’t seem to be pulling through so they can eat it ?‍. I pull some through the bars to start it off for them but I’m wondering as hay is a bit shorter than haylage strands whether they really can’t get it out after a while and they give up. Has anyone else had this problem?

 

[Roasted Chestnuts]

My dad made me my own one and it works great I’ve nEver known a horse not to be able to eat from one

 

[Mouse19]

My dad made me my own one and it works great I’ve nEver known a horse not to be able to eat from one

I’m surprised myself really that they are struggling. Not sure how long to persist. I put some on the floor too so they don’t go without overnight which they all eat and the munch station hay remains untouched after they’ve eaten the bits I’ve pulled through for them.