I’m so glad that worked for you..UPDATE: It seems all that was needed was a Factory Settings Reset. Picture proof now a Nintendo Account can be added. For the record, for "This Nintendo account cannot be used at this time, this user can't use online features" message and error code "2154-2005" after 6.2.0 update should be solved with a factory reset.
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Sometimes it’s the simple things.. it just didn’t make sense why Nintendo was not saying it was banned. Glad it workedI’m so glad that worked for you..