If I type the maximum value for a decimal (79228162514264337593543950335) and then try to increase the number through the arrow buttons, I get the following exception:

System.OverflowException: Value was either too large or too small for a Decimal.

The behavior is reproducible with or without setting the Max parameter to decimal.MaxValue: https://blazorrepl.telerik.com/mSuFwebI299wPCzV25.