Not that wrong, gromit. From your own link;
In July 2015, YPG and regime forces cooperated against ISIS during the Battle of Al-Hasakah.[28]
In July 2015, PYD leader Salih Muslim announced that the YPG was willing to join the Syrian army if the government committed to official decentralization of powers.[29]
On August 4, 2015, the YPG laid out terms for collaboration with the Syrian government.[30]
On August 9, 2015, in response to allegations of collaboration with the regime, a YPG spokesman issued a statement that the YPG will "collaborate with anyone to expel extremists" from northeastern Syria.[31]
On September 16, 2015, Syrian President Bashar al-Assad announced that Syria was open to decentralization proposals after the conflict between the government and opposition groups was over.[32]
On October 9, 2015, PYD officials reportedly held talks with representatives of the Syrian government and the Russian military in Damascus and Latakia about a joint effort against ISIS.[33]
On December 7, 2015, Assad affirmed that his government had supplied arms to the PYD, and said he had documents to verify his claim.[34]