It's possible that the glitch is only in our previewer, but won't export to the final versions. You may want to try exporting the file and proofing the ePub in Kindle Previewer to determine how the page will appear for readers.
If it is still a problem it may be that the automated Title Page just doesn't have enough room to display everything. Although you can't update the auto generated title page, you can customize a title page to fit your brand and style.
You can either:
Replace it with a Full Page Image
Click the Title Page in the left navigation pane
Since the newest update, you'll see a link near the top of that page that says Convert to Full Page Image
This option will give you the most flexibility to insert a full page image or a designed image of your book cover
Replace it with a standard chapter page
Delete the auto generated title page (click the little x beside the title when you hover over it)
Click add a New Chapter and replace the title and subtitle information with your book or part details.
I hope one of those options work out for you!