A leak maybe?

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Also: If you get a response it's polite to respond to it.

If you've been pulling oil/gas out before it was closed, the pressure at the bottom of the well was reduced to below "formation pressure". That was what was driving flow from the formation into the well's riser. Now you've closed the well, so the reduced pressure is rebuilding up to formation pressure as oil/gas within the formation is still slowly moving to the riser. The rate of increase in daily pressure should slow and level off when well pressure equals formation pressure again. The amount of time it takes to do that is an indicator of formation permeability and sustainable production rate.

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You need to look at the design of the well and what the annulus is connected to or suppose to be sealed off from.

What are the pressures of the annulus and the producing tubing??

Is the annulus exposed to the formation pressure or not?

Are there any connections between the tubing and the annulus??

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.