Problematic : difficult to deal with or to understand; full of problems; not certain to be successful.
This is the definition of the term problematic. Now, sometimes, native speakers sometimes confuse adverbs and adjectives. This happens in cases where the root word is both an adjective and an adverb.
The words hard and hardly are especially difficult. Hard is both an adjective and an adverb. You can say “The bed was hard,” using the adjective, which means it is “very firm.” You can also say, “I worked hard,” using the adverb, which means “with a lot of effort.”
Hardly is an adverb. A long time ago, it meant “in a hard manner,” but its meaning has changed. People used to say “not hardly.” Over time, the word “not” disappeared. Since the 1500s, hardly has meant “almost not” or “barely.” For example, “I hardly had time to finish the project.” This conflicting meaning of hard and hardly has become the basis for jokes.