It might be a pdf "flattening" problem; I've been seeing it when I have some fillable PDF's....and then when I send them out everything I 'filled' in is hidden .... PDF Expert on iPad/iPhone will 'flatten' to make it visible, and on Mac I use PDF Pro...but that may be the path to the problem?
GIMP. It's Open Source (free), but like any powerful graphics program has a steep learning curve. Paint.net is another good open source program. But, I agree with what some others have said, leave it to a pro.
Facebook had a glitch yesterday so it may not be on your end. Clear your cache, say 10 Our Fathers and 5 Hail Mary's, bury St Joseph, and restart the device.
Logomaker.com might be a cheap solution, but resist the urge to do it yourself. You sell real estate, right? Do what you are good at and let the designers design.
My wife, Realtor Ann Cummings, has been in contact with both Jeff and two fairly recent NAR presidents she knows. Both have been in contact with Laurie Janek, NAR's chief legal counsel, to research the problem and see what can be done. They both also contacted NAR's current leadership team to make them aware.