As others have pointed out, there is a problem. The most common is the rubber diaphragm
that allows for expansion is cracked. It is probably located on the bottom of the compass. The manufacturer typically sells them for ~ $15. Generally easy to replace.
The fluid is generally a thin mineral oil, but it varies with the compass. Match the viscosity of what comes out - something between very pure lamp oil, baby oil, but generally not mineral oil; it is too thick.
To get the last bubble out, burp it by pressing very lightly on the diaphragm
while screwing in the plug
Be gentle, and good luck.