Issue Summary

Value for a number-type custom field is saved truncated through REST API

Steps to Reproduce

This is a 2 scenarios problem, and requires clarification on which behavior is the correct one:
Scenario 1:

1. Create a number type custom field.
2. Add the custom field to the screens of any issue type.
3. Create an issue of that issue type.
4. Edit the issue and set the value to the custom number field to something with 4 or more digits after the decimal separator (like 9.987654321).

Scenario 2:

1. Create a number type custom field.
2. Add the custom field to the screens of any issue type.
3. Create an issue of that issue type.
4. Set the value of the custom number field to something with 4 or more digits after the decimal separator (like 9.987654321) using REST API (<base URL>/rest/api/2/issue/ {Issue key}

   )

Actual Results

Scenario 1: the value is saved entirely in the database, with the UI only showing 3 digits after the decimal separator (rounding up the last digit):

Scenario 2: the value is saved only with 3 digits after the decimal separator, with the 3rd digit rounded up:

Expected Results

At this moment, it is unknown which of the behaviors is the intended one, requires clarification.

Workaround

Currently, there is no known workaround for this behavior. A workaround will be added here when available