Yes you have a major problem
A T&P or Safety Or “Relief” valve is not supposed to seep.
It could be simply thermo expansion which in time will cause premature tank failure.
It could be a very defective spring inside this valve that is not allowing it to open fully.
Call a Licensed Master Plumber NOT a Fraud dabbling in Off the Wall installations and have this professional do a complete pressure vessel service.
T&P valves should be checked regularly and for a 3/4 T&P costing about $4.00 Watts brand you should consider having it replaced every two years.
The T&P is a unique valve in regard to how it is designed as it serves two functions.
1- Pressure vapor (safety)
2- Temperature (liquid) Relief
This is the only safety device on a residencial H/W heater.
A lot of folks install these tanks and forget about them.
They can be very dangerious if care is not taken to check them often.
Call a licensed professional and dont take chances.
NJ has a great training program for UA Mechanics I would contact a LMP in your area and have them find out what exactly going on in your system.