The R142A had issues while testing as well, I think the R143 is the only NTT car class that didn't have major issues when introduced AFAIK.
The R110B wasn't meant to last long like the R62A & R142, also the 110B's lasted longer than the Kawasaki made 110A. The R62A's are good cars and are holding up well same goes for the R142s, bombardier was still good when they built those fleets. Kawasaki is a tad bit overrated by railfans, it kind of annoying lol. People really think the R142A is a superior product to the 142s built by Bombardier?