The home I bought has 3 bedrooms each with a ceiling fan and single switch. I think these are Hunters, they have a remote and require T4 bulbs. These are not on the same circuit.
All 3 of these do the same thing when you flip the switch on. The light comes on at full strength, then after maybe 1 second, they dim to less than 50%.
I originally purchased 100W bulbs but then noticed inside the fixture it says 75W max, so I’ve now tried 75W T4 bulbs with the same result.
One professional installer (who wasn’t hired) told me that there was some power limiter in these fans that they routinely disabled on installation because of call-backs. I installed three of these fans myself in a relative’s house (no remotes) with existing ceiling fixtures and wall switches. I just followed the directions and so far no complaints. My wife had two similar Hunter fans with remotes installed in our house in rooms with no ceiling fixtures. Pressing and holding the light button brightens or dims the lights. The installers didn’t disable any power limiters present. No wall switches for our fans.
The absence of wall switches for our Hunter fans means I can’t replicate your report. Without a wall switch the receiver is always powered and I don’t have a major transient when using the button. I did have one failure with one of our two fan–neither light nor fan would come on. I assumed the connections were bad and I redid each connection in the fan shroud and it worked. Problem solved.
Then it did it again. Thinking the receiver was bad I removed it and wired the fan straight and we used the pull chains. Then I rigged up a test apparatus with a bulb as load and tested the receiver for both light and fan (using a single 40 W incandescent bulb as both load and indicator) and it passed all the tests. I reinstalled the receiver and it worked . . . but then had another failure. This time I just cycled the breaker on the circuit and the fan worked again, and has not failed for a year since.