...
Using Forge custom fields in other apps doesn’t always work as expected. Third party integration such as JXL or PowerBI can pose issues when trying to use Forge custom fields with the app. It is currently in plan to make CFS fields compatible with other apps.
...
Currency and Decimal fields formatting limitations in issue navigator
Currency Fields require a custom display to showcase both the currency symbol and the numerical value. Due to this manual rendering and storage as an object with multiple properties (as opposed to a simple number), Jira does not apply its standard number formatting. Additionally, Jira Expressions, which we use to display these values, do not support complex formatting operations. As a result:
Currency values may not reflect the user's locale-specific number formatting.
Rounding to two decimal places is possible but will still not align with locale settings.
Decimal Fields might omit decimals when full numbers are entered.
...