Using scroll tabs arrows causes page reload on spreadsheet. This is the two arrows at the bottom right on the spreadsheet control when tabs go off the screen.
This only seems to happen when the spreadsheet is between <form></form> elements. Take these out and it works as expected.
See this dojo: https://dojo.telerik.com/HXscWjdD/2
Did a setting change? This did not happen in earlier versions.