I have seen many similar posts regarding the Sylvania/Osram bulbs. In addition, I have seen posts where users describe Zigbee HA1.2 mesh network instabilities caused by these bulbs (as well as GE Link and Cree bulbs.)
I personally only use Sengled bulbs if they are to be directly paired to my Hubitat hub. Sengled bulbs are inexpensive, reliable, and are designed to NOT be zigbee repeaters. Therefore, they will not try to act as a zigbee repeater, and thus will not negatively impact your zigbee network, even if they are switched off.
