4wd "limbo mode" issue

I am a 17 year old and have a 1999 4runner limited with roughly 137,000 miles on it as my daily driver. My family is the second owner and have had it since 2002. Recently anytime I have to use the 4wd for longer amounts of time, it will enter "limbo mode" (the flashing indicator) as it would if it was engaging/disengaging 4wd. usually it will enter the "locked in" 4wd mode once, before it begins flashing again for the duration of the drive. So far, the only fix I have found is to turn off the vehicle and let it sit for an hour or so to let the computer reset. None of the other normal tricks work. I found this forum in my research https://www.yotatech.com/forums/f2/4...er-ltd-131201/ and it makes me believe that I have a similar issue. However, in 2023 the part is $91 instead of $36, so it's not as much of a throwaway fix that I can just try. Also, I am a beginner mechanic at best, so any fixes will likely have to be done at my mechanic (he's incredible so no worries there), and I have an appointment scheduled in a week to replace the suspension anyway so I was hoping I could do this at the same time. I was wondering if anyone has had a similar issue or has any other ideas on what it could be before I just go out and buy the part. Feel free to ask any questions and I would be happy to answer to the best of my ability. I appreciate any advice.

 

Any codes from the OBD?

 

no check engine codes