I've also seen several complaints online from others about the same issue. Some have said they called Contigo and were sent a new lid. With that said, I would recommend you call Contigo BEFORE you disassemble your lid! But if you've already disassembled the lid to clean it (like me) or if you plan to do so b/c you don't have time to wait for a new lid, then this "how to" is just for you!
Oh, and this is my first ible! Be nice. I apologize for the poor camera work. If you notice any mistakes or need something clarified, please don't hesitate to comment below. Thanks & enjoy!
Step 1: Parts and Tools
Tools: beater from hand mixer (best option) OR anything strong w/ a rounded tip. I would NOT recommend anything sharp.
Step 2: Insert Seal Into Mouthpiece
Use the beater tip to press the outside of the seal into the mouthpiece. The 2nd pic shows the seal partially in (lower part) and partially out still (upper). Your lid should now look like pics 3 & 4.
Step 3: Insert Seal Into Lid
This part is a little tricky. Use the beater tip to press the seal into the lid. I pushed the right side of the seal in first (pic 2), then snapped the mouthpiece into place (pic 3), then pressed the left side in last (pic 4).
When the seal is inserted completely, it will look like pic 6, not pic 5.
Step 4: Add Straw and Screw on Lid
Then just screw the lid back onto the bottle and test it out.
Hopefully everything went well, and you can get back to serving your kids using these (mostly) amazing bottles! Thanks for reading my ible! I hope you found it to be helpful. Have a blessed day :)