Validation not given for minimum account number and maximum account number

Steps:

1. Install add on of Account range
2. Now go to configurations > Account
3. Now enter invalid data for Minimum Account Number & Maximum Account Number field.
like Minimum Account Number= '999999999999999' and Maximum Account
Number='00111111'
4. Now save the record.

Expected result : Validation message should be display for Minimum Account Number & Maximum Account Number field. Because Minimum number should be less than Maximum number.

Actual result : Validation message is not display and record saved successfully.