How much storage space is allotted for apps and watch face installation?

Hi,

first of all, sorry my screenshots are in Korean, but I guess it's quite clear what problem I am facing.

I was constantly getting Connect IQ app notification saying "not enough space" to install app updates.

I didn't bother looking into it since I knew Garmin Venu has 4GB storage space.

To my surprise, Connect IQ only recognizes 4+ MBs, and that is after a factory reset.

Once I install 2 watch faces and amazon music app (without downloading my music library),

I would run out of storage space and can't even install updates.

When connected to a PC via USB, the full capacity is recognized as an external storage device as shown below, 

but I still cannot install more than 2 apps or watch faces.

Is this a firmware issue or my unit is simply defective?

Thank you.