Welcome to the forum @[email protected].
Nice initial break in ride! Yes, that battery cover panel is one of the very few problem parts. Keeping it tight is an issue. I mentioned in that thread that Huladog linked to that this is something that is covered... but best handled by the dealer selling the bike to you if it is a matter of a broken tab. If the tab is not broken, yet still gaps as some do, then there is no warranty for that to my knowledge. There are a few things to do that might resolve the fit, but not all options work for everyone. To me it's a minor thing. While the engine and most of the mechanicals in this bike have a 13 year history of reliability in the ST1300, the plastics are new to this model so some issues are to be expected there.