UPDATE - tested all the wires with a multimeter, WHITE - Neutral to GROUND - no reading, BLACK - Hot- to GROUND no reading, BLACK - Hot to WHITE Neutral no reading. When using a no contact voltage tester the WHITE - Neutral is beeping and giving me a warning, the BLACK - Hot isn't and so is the GROUND. I traced all the junctions and they are all wired correctly and tests correctly.
I just installed a GFCI outlet to an outdated backyard outlet that was just conventional outlet without any protection. Upon testing with an outlet tester, it reads 1-RED 2-Yellow 3-off hot and neutral reversed. I tested the outlet TEST and tripped successfully, and then RESET properly. Then I tested it again with the outlet tester and still reads the same 1-RED 2-Yellow 3-off hot and neutral reversed. Should I be concerned? What is causing this?
Some context, this is a 3 wire (hot, neutral and ground), when I turned off the breaker circuit for this line, its associated with the garage lights, half bath lights, and the backyard lights. I connected the wires to the LINE connections of the outlet.