The bug occurs for Uthmani Script Unicode Madani Mushaf and not in the Indo-Pak version.

Based on the policy followed by the app, Juz 4 starts at Al Imran (3) - 93 and Juz 5 starts at An Nisa (4) - 24. These have proper Juz markers. However, the quarterly count between 3:93 to 4:24 are messed up, with a repeated Juz 4 appearing at Al Imran 171. Each quarterly Juz marker between these are repeated as well, before and after.