Delta Trinsic Tub spout

[DIY_Noob]

Hi,

At a frustrating standstill trying to complete month’s long remodel. Worked with a friend to install a shower and bath but missed the very obvious direction to not use PEX for the drop to the Spout. Shower and bath simultaneously running was my clue to this issue. Also very low flow from tub spot. Good flow from shower when gate lifted.

I’m a little leery of trying to sweat the copper inside the wall and so I tried shark bite copper solution. Appear to still have the same issue. As a first step I’m wondering if you all have some suggestions on how I might troubleshoot this. Heck, might even know what I should do.
Thank you in advance.

 

[Reach4]

Look up "twin ell". If you could connect the spout to one of these, that could fix it. Even if the water from the valve connected with pex, that would work.

Mechanically holding it in place could be the problem if the twin ell is not held in place by being connected by copper pipe. You might be able to approximate this in other fittings. The point is that you want the tee down by the spout. I don't have it worked out how you can do this. I am not a plumber.