Tub spigot

I have a tub spigot that isn't snug to the surround and even has some play when the plunger for the shower is activated (the plunger is in the spigot). House is plumbed with PEX.

Going to attempt to correct this, but I have a few questions:
I cannot locate a set screw for the spigot so I assume it's a screw on. I have tried to turn it, but it won't. Can the PEX fitting spin if the spigot is frozen, and can that cause damage to the PEX?

I'm trying to keep from opening up the backside of the wall.

Thanks to all.
Alan

.... Can the PEX fitting spin if the spigot is frozen, and can that cause damage to the PEX?...

It's almost guaranteed if you have pex comming to the spout and the spout is screwed on you will damage it trying to get it off, sorry

While it is fine to bring pex TO the valve, between the valve and the spout and up to the showerhead, it is highly recommended to run that in copper. Not sure how they would have gotten a screw-on spout attached to pex. Plus, because pex is smaller ID than copper, often the restriction to the tub spout will cause water to back up into the shower riser and out the head, even when the diverter is not set. To make the spout stable, you need rigid materials anchored to blocking or the wall, and not possible with pex as the outlet.

The pipe from the valve should be secured to the framing inside the wall, but if that had been done the spout would NOT wiggle. If it is not secured, and the spout does not readily unscrew from the pipe, you will almost definitely damage something if PEX is involved. Either snap the pipe down to the elbow, or rotate an adapter inside the spout. At this point your safest bet is to cut the spout in two so you can see how it was attached.

Was able to get a small inspection mirror inside the valve cutout. The spigot is fed with copper as is the showerhead from the valve with both supplies being PEX.

However, there is no blocking anywhere. Not behind the valve, not behind the spigot. Couldn't tell about the showerhead. Guess the wall will have to come open.

Thanks for taking the time to help.

Alan