Throttle response sag

[Newnoob]

Hello everybody, I hope you are all well!
I am completely new to the motorcycle world at 28 years old and the varadero 125 is my introductory bike.
It is a 2001 model with 80.000 km on its back, in very nice condition.
The only problem I have after I bought it and procceded with the regular maintenance work- cab cleaning, filters etc- is that the throttle has a very sluggish response especially when reaching optimal temperature.

What's happening is that when I am, say at a stoplight, I rev the throttle to get to around 5k rpm so I can take off at a decent speed- you know how those bikes have to be treated to get some minimal juice out of them- BUT the throttle doesn't respond even with the clutch all the way enganged. I have to wait around 2 seconds before the engine revs up so I can hit enough rpm to be able to disengage the clutch and go.

Any advice or anyone that can share any similar experience and solution to this problem would be greatly appreciated as this is a very annoying thing when you want response on the road, as well as a safety issue potentially.
Best regards,
John