On the view options of modern UX, using the Smart Filter option "End of Current Year" ends the per period metrics prematurely instead of going to the end of the year.
Clarity PPM 16.x
The issue is identified to be an incorrect fiscal year setting for a Monthly period in between the year.
Ex :- Setting the May 2026 period to Fiscal Year 2025 will cause the Per Period metrics to stop at April 2026 when "End of Current Year" is selected.
Modifying the problematic periods Fiscal Year to the correct year resolves the issue.