Can "dirty" SWCG cell impact pressure to water features?

[poolnoobgrandma]

You state that your pool was built this past summer. I would call builder and have him send someone to check it out. A lot of times they do sloppy work with the plastering, and pvc lines get partially plugged and need to be cleared. I was picking out plaster that was almost golf ball size from my pump filter basket for at least a year. Had one line to spa that they had to come out and clear.
Feel your supply outlets to spa to check for good pressure, should be about the same for all of them in the pool.

Agree. I dug some plaster "rocks" out of a pool return jet last summer, and after I had turned ONLY the spa valve on to put additional pressure through the pipes to the spa, there were a bunch of rocks beside the spa drain.

Sigh. Guess it's a call to the PB.