Is it true that some scholars sometimes act upon a weak hadith and not upon an authentic hadith?

In the religion of Allah, nothing is used as an argument from the ahadith except what has been authentically narrated from the Prophet, peace and blessings be upon him. The sahih (authentic) hadith is that upon which the hujjah (proof/argument) is established. If the conditions of authenticity are met in a hadith, then it is a hujjah and must be acted upon by the consensus of the Ummah. If some scholars abandon acting upon a hadith that meets the conditions of authenticity according to them, this is due to the presence of another evidence they consider more preponderant than this hadith. The way forward when there is a contradiction between evidences is to give preference to one over the other. As for the da'if (weak) hadith, it is not acted upon. However, the meaning of a weak hadith might be acted upon if there is something that indicates the correctness of this meaning, even if its isnad (chain of narration) is not authentic. This could be if the meaning of the hadith is something upon which scholars have reached a consensus, or it is supported by the practice of the predecessors, or its weakness is minor and acting upon it involves caution.