The phrase "a challenging issue and" is correct and usable in written English.
It can be used when discussing a difficult topic or problem that requires attention or resolution, often leading into further explanation or elaboration.
Example: "The report highlights a challenging issue and suggests several potential solutions to address it."
Alternatives: "a difficult matter and" or "a complex problem and".
The use of dynamic approaches to assess how these species will respond to climate change is a challenging issue and mechanistic models able to incorporate biological and evolutionary processes are a promising tool.
Therefore, PU authentication is a challenging issue and existing proposals are subject to practical limitations [53].
Selecting proper values for them is a challenging issue and requires analysis.
The extraction of IF-THEN rules in the FRBIS is always a challenging issue and is highly affected by the knowledge and skillfulness of the decision maker.
The development of appropriate protection devices and strategies for MTDC grids is a challenging issue, and the lack of efficient protection strategies is a biting constraint on the pace of development of MTDC technology.
Sending multimedia traffic over wireless ad hoc networks is a challenging issue, and many active research areas exist that all try to propose a solution to the problem from different points of view.
Salvage treatment of recurrent GBM remains a challenging issue for neurosurgeons and needs a multidisciplinary approach including radiotherapists and oncologists.
So minimizing the energy usage of data centers is a challenging issue because applications and data size are growing very rapidly which require fast servers and large disk storage to process service request within the defined time period.
Long-term stability of large-span caverns is a challenging issue for design and construction of underground rock engineering.
Investing in R&D for a product employing new technologies is a challenging issue for companies and governments alike, especially at the critical juncture of deciding the degree of resource allocation, if any.
Computer security is a challenging issue in general, and networked armadas of computers on wheels will be attractive hacking targets.
