Print on their side like the clips in the original model.
The author remixed this model.
This is a remix only of the side clip. For whatever reason the side clips in the original files were ever so slightly too short, even though the rest of the print worked excellent. I wasn't able to snap the side clips in when two frames were side by side.
I modelled a new side clip, keeping the dimensions on the original with the exception of the total length of the clip which I increased by 0.8mm. This clip works great for me, the frames are tight but fit.
Use these clips if you have the same issue as I did, but I'd start with the clips from the original model first.