gear backlash when starting in 1st gear?

That's basically it. Like a quarter second before bike starts moving.  It may be a new issue or maybe I just never noticed.  Haven't ridden it much last few years.

When I first start out I'll notice it, and if I stop and start again it won't happen.  Will be just like any other bike.  Like something loose in drive train.

Does this sound serious?

You’ll have to try and explain it a bit better. I have no idea what you could be describing…..?

So lets say you have a splined shaft like the driveshaft, and it doesn't fit so like one half is narrow splines and the other side is wide grooves. When you start out it might move some before proper engagement. Thereafter it remains fully engaged. Seems something like that.

Sorry. Not helping. I’m not trying to be obtuse, I just can’t imagine what is happening.

Are you saying that you release the clutch and nothing happens, and then the bike creeps off with no input from you?

I think they're saying there's slow or delayed clutch take up. You release the clutch and the drive train doesn't engage for a couple of hundred milliseconds.

My old 2012 GRiSO I had, would feel like that sometimes in 1st gear, I only started noticing it once on a 7000mi trip  about halfway through...It worried me at first but it never got any worse over the remaining 3000 miles and then I just forgot about it..it as like a hotrod car when you have  a Detroit locker rearend backlash,  its in gear but if you slightly let up on it when first starting out and then reapplied throttle there was a slight little slack or backlash....I talked with some other experienced/knowledgable Guzzistas about it at the time but we never figured it out ..so just forgot about it.
( I suspected its like Beetle suggested something to do with the clutch engagement thats not to worry about)

How old is the clutch fluid? Suggest flushing and refilling...especially if the bike hasn't been ridden in several years.

My thoughts were drifting towards failing or gummy seals in the master or slave cylinders for the clutch. Certainly if the fluid hasn’t been changed regularly it needs doing. Yearly or every 10,000km is my schedule.