"tenacious issue" is a correct and usable phrase in written English
Example: She faced a tenacious issue when trying to pass the difficult test.
Current development is however hindered by some tenacious issues of the sulfur cathode; resulting in the use of excess conducting additive or operations in a smaller voltage window (where the active sulfur species are soluble).
He promises to be just as tenacious on this issue.
"I think people will tell you I'm pretty tenacious on an issue.
They've come this far by being dedicated, tenacious, deeply informed on the issue and on board policy, and by regularly meeting among themselves and attending most of the meetings.
And there are just enough loose threads in both issues for a tenacious prosecutor like Gowdy to grab hold of.
Limited space was an issue, "but essentially we were just tenacious in getting it done, and now the administration is very excited about what we're doing".
"She was energetic and tenacious in her efforts to focus on the core issues that people care about.
The negotiator must be persuasive, flexible, tenacious, and creative in devising new solutions or reframing issues from a new angle to convince the other party that agreement is in its interest.
Thomas did not concern himself with the church state issues surrounding the Investiture Crisis, but he was tenacious in defending the independence of York against the efforts of Canterbury to assert primacy over the whole of England.
My father's partner is tenacious, smart and a bit tougher but I have never really had an issue with him.
