Hi Marcel Souza,
Greetings from Syncfusion.
We were able to reproduce the reported issue "Buttons control (SfChipGroup, SfButton) takes the whole width of its parent layout while upgrading the Xamarin.Forms version". We have already known this issue and logged a defect report on this.
The fix will be available in our upcoming Volume 2 main release which will be expected to be rolled out at mid of July 2019.
If you have any more specification/precise replication procedure or a scenario to be tested, you can add it as a comment in the portal.
Thanks,
Muneesh Kumar G.