Just found this on my Premier outdoor kitchen and was going to post as a warning for others. You beat me to it. It seems so simple to just put a drop of sealant on those at the factory! Sorry you had to rebuild yours.
I don't "feel" any rot in there but I'm sure there is some hidden water damage. At least the screws were still tight. I don't understand why the screws would be on the outside of the seal.
Or why there is not a drop of sealant in sight on any of them.