I am probably late for this and if so, just disregard this. 😉 I always wipe the rims of my jars before I put the lid on in case of dust or crumbs. Wide mouth lids always seal perfectly. I have found several times with the regular mouth that I have to put an extra regular lid on top upside down to get the other one to vacuum seal. Another tip is pull out your hose from the jar sealer before taking it off of your jar, you will hear the whoosh but it doesn't break the vacuum. The blue rubber ring nearly always comes out for me, as many others have said the same thing. I use a paper muffin liner, (coffee filter works too) in the top of all jars that are powdery, it stops the powder from going into my machine and ruining it. I do lots of pasta, flour, and rice in the bags, I portion them into brown paper lunch bags first (especially sharp pasta) and then vacuum seal in a bag. I put all egg noodles and fragile type pasta in jars. And most cereals like rice Chex, flakes and crisp rice, but do not vacuum seal raisins or dried fruit. Must have 10% or less moisture content, or you could grow botulism. You DO NOT have to freeze first if you are removing all of the oxygen, everything dies without oxygen after 12 to 14 days 😁. If I only have a 5 lb bag of flour I leave it in the paper bag, pierce the bag in two places near the top and vacuum seal. Do not vacuum seal sugar, you will end up with a rock, lol. Meats should be frozen first if possible, otherwise I will place a folded paper towel inside the width of the bag so if any liquid starts to come toward the top it will catch it and I stop the vacuum and go ahead and seal the bag. One other thing that might be helpful, I get my bags and rolls to make custom sizes from Amazon, they are Avid Armor, I have not had one to fail. I did have 4 failures from the Foodsaver brand, 3 were meats and 1 was a bag of flour. Sorry, 😂 can you tell I am all about details and want everyone to succeed, lol? God bless you!

Where did you buy the lids?