Grains that are sterile and properly hydrated wouldn’t get juicy from shaking, from what I’ve seen. Could be a bacterial issue.
I am old school with jars, but just three small nail holes, flip the inner lid so the pointy parts are up then a tyvek layer or similar under the seam. I use agar though not syringes, all SAB friendly.
All the gluing and such just adds failure points IMO. My last run was 84 jars over 3 months and only lost a few to contam, has a batch of overcooked grain that I pitched the 5 other anyway because the hydration sucked, and 1 other that I fumbled the transfer on and it got SAB floor germs.
Post some pics or pm me if you want, happy to help-