Well, check to see if the seal is seated right first since you have taken it apart and together again. Thats 1.
( easy fix but not really recommended )
( Advanced fix but makes it good as new )
Step 3 I will not advice you to do if you have no experience with drills or things like that. But this is better to do with your hands ofc.
Cause you need to "drill"or tap a new bigger hole and insert new threads (glue it in place ofc ). The link I gave you is one way to do it, but you can also use a special tool to make new threads into the acrylic. ( see last link )
If you wanna try step 3 nevertheless without any experience. Go get a sheet of acrylic about 5-6 mm thick or more and practice on that.