正面: the front of a building and facing a problem head-on
Compare a clock at the front of a building with facing a difficult problem head-on. Read 正面 as a physical front or an attitude toward a problem without assuming the problem was solved.
The clock's position on the building
正面（しょうめん） means front or head-on. 「建物の正面に大きな時計がある。」 states that there is a large clock on the front of the building. 建物の正面 identifies the clock's position on a physical front face.
ある states that the clock exists there. Its large size and front position are given, but who installed it and when are not. 正面 in this example describes a place, rather than someone's attitude.
Facing the problem without avoiding it
「難しい問題から逃げず、正面から向き合った。」 reports facing a difficult problem head-on without avoiding it. 正面から describes a direct attitude toward the problem, rather than a physical face of a building.
逃げず expresses without avoiding, and 向き合った reports the action in the past. The sentence establishes that the problem was faced directly. It does not state that the problem was solved or that the response was aggressive.
Check whether the sentence gives a place or an attitude
In the clock example, 建物 and ある guide you to the position of an object. In the problem example, 問題 and 向き合った guide you to the way a problem was faced. The surrounding noun and verb distinguish the focus of 正面.
Keep the physical front and the direct attitude in their respective contexts. In particular, the past action in the problem example reports a response to the problem; it does not include an unstated later outcome.
Does 正面から向き合った mean that the problem has already been solved?
Show the answer and why
It means the problem was faced directly without avoidance. 向き合った reports that action in the past, but does not give a solution outcome. 正面 in the building example instead identifies the physical front where the clock is located.