Hi,
The first issue you mentioned is not possible to fix. For further information see here: The TMSFNCCombobox behaves wrong under Windows10 (Delphi 10.4, VCL+FMX).
As for the second issue, you cannot change this behavior currently. To improve this, we introduced the AutoFilter property to disable the filtering of the list, you'll need to set it to False. The next update will contain the changes for this.