This Cooper CFB has been cycling for many years and I haven't noticed it all this time. Earlier in the week, I noticed Brookline Public Works transferring the light and an LED Roadway NXT to a new pole. I asked them about the cycling and they should replace the ballast and lamp later in the month. I decided to record it a day before BPW came, sorry for the shakiness.
Video link:
https://youtu.be/fAuKq7q-NYI