Thanks for your feedback, your help is greatly appreciated as navigation from links within PDF documents is an important use case for us. We build the open-source software Safe Exam Browser, and many professors at our university use links within PDF documents which they provide as reference to the students during their exams.
What URL are you loading the PDF from? Is the clicked link a relative or absolute URL?
We can reproduce the issue when directly loading a local PDF document via a
file://-URL as well as when placing a PDF document on a server and loading it via HTTPS, and it furthermore behaves exactly the same in our software as well as in the CEF sample application. The links in our test document are all absolute HTTPS URLs.
Does the problem reproduce with older/newer CEF versions?
We had another issue regarding navigation with modifier keys recently (February 2021), and in that context our testing verified that links within PDFs work as expected. In the meantime, we updated from CEF version 87.1.13 to CEF version 90.6.5 and thus we suspect that this might be a regression or a new bug introduced in Chromium or CEF.