Rear led tail lights not working properly

2008 Tacoma led taillights not working properly. Checked fuses, replaced the two bulbs that is replaceable. Replaced sensor inside behind brake pedal. Parts store said left circuit board bad so I Ordered same assemblies for both sides, replaced, still same problem.
Problem: turn signals both work. When lights are on, neither brake light works. Right side lit up as if riding the brake. Left side nothing. In the daytime w lights switched off, I have right side brake light only, left side nothing. Feeling disgusted after spending $275 on new assemblies that didn’t fix the problems. Any suggestions would be appreciated. Is this probably a simple fix that local shop should be able to handle or anything else I could try myself? I’m not too mechanically inclined myself and really hoped the assembly replacing would fix this.

 

Considering they get power and ground from the same source it would seem you have one or more broken/corroded wires or a bad ground at Ground Point BD.