Looks pretty lousy, but what appeared to be the cause of water all of a sudden starting to leak?

While lots looks poor there, dirt and foreign objects come to mind...

Im pretty sure it's low on gas. Her main unit in the living room is a 12,000 btu that was flashing a code. I don't want to mess with it since i didnt install it...... untill i get the go ahead from the company that sold it to her.

not minisplit related but...
a metal building with metal studs & fiberglass
batts...she is going to have one heck of a
utility bill.
what I've learned over the years is how
highly conductive the metal studs are
to the point of derating the fg batts to very
low R-values.

heat/cold transfers very well from shell to
studs. in my hot/humid climate the
wall studs condensate through the sheetrock
in the late summer. with paneling ...which is
thinner..I'd worry about this issue in this small
house.

the only way we get these homes to perform
is to thermally break the walls by putting
a foam sheathing board next to studs, under
metal siding...and roof. well...there is always
foam in the studs/rafter bays but the sheathing
is a less cost install.

at 1,000 sq ft and two ton minisplit...with all
the openings in the paneling tha should have
been sealed during the install of the minisplit...
I'd run lowest speeds, and seal each opening
in the paneling..at each ahu.

what is the location of the house?

best of luck.

Its located deep in S.Texas. It actually has 3 indoor units, 2-9000btu's and 1-12,000btu, so 2.5 tons total. Her complaint isnt that it doesnt cool well, its that the house is less than a year old and 2 of the 3 indoor units are not working properly. I believe also that they framed the inside with 2"X4"'s insted of metal studs. If you look closely at the 1st, 4th & 5th pictures, you can barely see the wooden studs behind the paneling.