Assume that is a Williams Gulfstream. To ease the opening it looks as though the wireform at the top could be eased to the left and the broken plastic which has been ballooned from the rubber could be returned to its original form by carefully using a hair dryer or trimmed. Sometimes it is also possible to get some movement in post alignment.

Turn the plastic around,broken end on the other side

...or replace. Sounds like Wariodolby has your solution...

You can also use post rubbers there instead of a ring to relieve the pressure. Unless the other side is open

You can also use an adhesive to glue the split plastic back together again.

That makes sense. Is there a switch there?

The new rubber is fatter than older.... maybe go down a size to help thin it out. That's not great for wood screw posts though, too much force pulling in.

I'd probably see if you can move the post to the right a little. Maybe fill n drill a new hole if needed, or if the metal guide can be tweaked to the left.

As a quick hack fix you could just rip off the offending plastic part

Yeah that rubber ring looks fatter than normal. Maybe a size smaller and a ring on each post instead or a loop around both if it's not already like that.

It needs the full rubber to protect the bulb.

If it were me, I'd try a lane guide with both sides and change to having a post rubber on each like you suggested. But, that may cause the lane guide to get cracked on the side closest to the bumper, so it's a crapshoot.

Your ball looks like it needs to be replaced.

I had the exact same problem on my Gulfstream when I restored it. Bottom line, it came down to the post holes stripping out over time. I filled the holes and moved the post over about 1/16”. Have not had any issues in 6 years.