Rendering problem on some PDF files.

[PeaceGiver]

I notice that there's some rendering problem on some PDF files.
I bought FlexiPDF 2022 from Ashampoo and preordered 2025 version, and I tried trial verion of FlexiPDF 2025 from official site. Both 2022 and 2025 cannot render it correctly.
This is the PDF file I using to test PDF reader or editors.

T客邦好友禮，【10個ChatGPT的好工具】電子書.pdf

This is the PDF file I using to test PDF readers/editors.

(39.05 MiB) Downloaded 55 times

[SuperTech]

Please share some more details of the problem like where exactly you are getting this problem, screenshot of the problem etc.