The non-binding resolution was passed with overwhelming support from the Republican majority, setting them squarely against parts of President Trump’s foreign policy. A number of Democrats who voted against it expressed concern that it was tantamount to a vote advocating a state of permanent war.
Which it realistically is. The 2001 authorization for the Afghan War was built around 9/11 and the defeat of al-Qaeda. Neither are hugely relevant issues in 2019 Afghanistan, and a peace treaty being negotiated centers heavily around the Taliban promising to keep al-Qaeda and ISIS out of the country in the future.
Congress never actually authorized the war in Syria at all, dodging that obligation repeatedly because of political concerns. President Obama invaded Syria unilaterally to “fight ISIS,” and President Trump has declared ISIS effectively defeated now that they have virtually no territory left.
Leaving Syria has become a political hot-button issue for many hawks, who argue variously that either ISIS isn’t defeated, that the US should transition the Syria War to fighting Iran, or that the US should transition the Syria War into permanently protecting the Syrian Kurdish groups the US was aligned with against Turkey. Within the administration, a number of hawks oppose leaving Syria just because the broad assumption was that the US would always be there.