Bugs in production software existed in all generations. In the mid 80s I worked on DEC Vax VMS systems. Our code was mostly written in FORTRAN and Assembly Language. Our group dealt with the failures of the dev tools and bugs in the OS. Once we eliminated the fault was in our code (non trivial effort) we brought the proof of the problem to the vendor who responded in a not unreasonable time.( We did buy millions of dollars of equipment from them)

Bugs existed in the early 90's DOS and Windows environments and we worked around them with no vendor support. Bugs existed in the mid 90's web dev and we worked around them.