Thank you for your post.
I am unable to replicate the issue. On my Windows 10 Pro machine, the Launch Center appears every time FileMaker Pro 16 is launched.
Is FileMaker Pro 16 installed on the default C: drive? Is FileMaker Pro installed to the C: drive.
C: -> Program Files -> FileMaker -> FileMaker Pro 16
If you create a new Windows account, login to the new Windows account, launch FileMaker Pro, does the Launch Center appear every time?
I converted my account from a Cloud-based account to a Local account and this fixed the problem for me.