After installation, I have had problems with pixeling and buffering particularly on one affiliate. I had previously installed a new router. We have 2 zone HVAC with Nexia xl824 Smart (sort of) thermostats that are on the intranet. The password was not updated and both were trying repeatedly to log on. I reset both. So far, so good!
Plenum blower motors can be a problem too if not WELL grounded. Our plenums are metal rather than “glue board” because of allergies. If the metal isn’t bonded electrically to ground, it can make a wonderful antenna to broadcast interference. You might need a pro for this problem.
Pixeling still was present and maintenance showed all HVAC grounded. Needed to replace modem which was near router. Problem solved.