Moisture Patches in Wall

[Nicolas Pretelt]

Hi all,

recently move to a new house hack. Duplex was completely remodeled but one of the walls started to have some "moisture patches"

It is only a portion of 1 wall and only in the downstairs unit. Upstairs unit does not have it.

There was tuck pointing done recently but there are some small holes that we are thinking of covering.

any suggestions on what it could be and how to fix it?

Thanks