Coolent System Questionable

So my coolent system has me under suspicion. The coolent is leaking not a lot but seeping from the radiator cap and the hose that goes into the reservoir. Last year had water pump replaced this month had a coolent flush. Truck is holding coolent levels fine not overheating or anything but before I face a legit breakdown trying to figure this #### out btw it’s a 2017 Freightliner Cascadia w/501,525 miles. I’m suggesting it’s either the radiator cap needs replacing of thermostat hopefully it’s sum like that on the inexpensive side before I drop a few thousand into a radiator please let me kno sum

 

Injector cup seals?? What’s that?? N where is it at how much it cost and can I do it myself

 

Plus coolent is new just had system flushed n new fluid replenished literally like last week at dealership

 

Nahh the level is right jus had a coolent flush at dealership I double checked it to make sure it wasn’t over filled