Feel free to bring the flame, but IMHO one day in secondary is bad, even with activity.
Wow, as one of the biggest proponents of long primary brewing on here, even I'm not arrogant enough to say that.
As I end the uber post summing up both arguments for WHEN to rack to secondary should one choose to use it;
https://www.homebrewtalk.com/f39/multiple-questions-about-secondary-fermentation-140978/#post1601829
But this is the important takeaway message...
The good news is that whatever method you choose, you will STILL make great beer. That's the amazing thing about this hobby. There is really no RIGHT way of doing things. There are literally dozens of ways to skin the cat here, and all that matter is integrating whatever methodology works best for you into YOUR OWN UNIQUE brewing process.
As in most of brewing there is no BEST or Better way of doing things, it's only our
preffered way. People who chose to use secondaries can make great or crappy beers, just like those of us who choose not to secondary can make great or crappy beers.
It is just what one prefers for THEIR individual process.
Now as to the original question.....If you are using the secondary for the purpose of clearing the beer, then you should have any more fermentation happening, and unless there is some trapped co2 breaking from the trub, you won't see any bubbling. Remember,
airlock activity is really not that important in terms of telling you what your beer is doing. An airlock is a vent to belled off excess co2...NOT a calibrated fermentation gauge. Many of us have beautiful fermentations with nary a blip of an airlock. And other times the airlock bubbles.
But if it doesn't bubble, either in primary or secondary, ir really isn't anything to be overly concerned about. There are other more reliable methods of letting you know what your beer's doing...the most reliable is with a hydromter, and of less reliability, but still important, our eyes telling up whether or not a krausen rose and or fell on the top of the beer. But not your airlock.
Hope this helps.