@vladimir.litvinchik - It was the media middleware issue which was intercepting, so that’s now resolved. Other mentioned 4 issues are now sorted. Thank you.
With 8.1.2 - Letter size pdf pages are not fully visible on 100% default zoom level (need to scroll). Also There is no intermediate zoom level between 50 and 100 that we can explicitly set.
Previous 100 percent on 8.0.7 was properly resizing the page (no need to scroll)
Note - We load the viewer within iframe as below within cshtml file.
<iframe src="/viewer?file=sample_letter_size_5pages.pdf"
name="targetframe"
allowTransparency="true"
scrolling="no"
frameborder="0"
style="height:1200px;width:100%;"
id="groupdocs_viewer_frame_1">
</iframe>
Viewer_8.0.7_LetterSizePage_FullyVisibleOn100PercentZoom.png (29.6 KB)
sample_letter_size_5pages.pdf (3.7 KB)
Viewer_8.2.1_LetterSizePage_NotFullyVisibleOn100PercentZoom.png (36.4 KB)
I have attached screenshots and sample pdf for reference