Newly Installed Bifold Doors Difficult To Initiate Closure When Fully Opened
Ed Beal &amp; User3757614 are very right. However, see if you already have stops that are integrated with the door anchors at the ends. If you have them, they're adjustable &amp; keep the rollers from binding in the track, which sounds like is your problem. The doors shouldn't collapse tightly together.

There would be a screw at the outer edge of the anchor &amp; you may notice a seam between a thin edge piece of metal or plastic that you may have mistaken as a bumper or cap. This, would or could be your adjustable stop that can be extended out again to where the binding is avoided.

This is a common problem &amp; everyone eventually leans on the collapsed doors to push the stops in or never extends them in the first place. Due to leveling issues some people leave or make the binding to hold the doors open to stop the doors from closing on them, it's very annoying.