Every major group needs a sponsor. And if we speak of "major world terroristic groups" they all are state-sponsored. So let's talk about world policy instead.
Qatar and Saudi Arabia were active sponsors of so-called "Arab spring" starting from the very beginning in 2010-2011. Usually both states were seen as friends to each other, but clearly their interests can not always coincide. For example, in Egypt Qatar showed open support for "Muslim brotherhood" who are viewed as "terrorists" by Saudi Arabia.
In 2011 the coalition led by USA, UK, France, Saudi Arabia, Qatar, Turkey, Israel and other states attacked Syria. Until late 2013 they all were allies but then something changed (Egyptian coup d'etat 2013? More conflicting interests?). And so Qatar-sponsored ISIS appeared as a new major force in the Syrian war.
In January-February 2014 ISIS and Saudi-sponsored Al-Qaeda entered in direct confrontation. On 5th March 2014 KSA, Bahrain and UAE recalled envoys to Qatar, because of "interference with their internal affairs". Inofficially they speak of "Muslim brotherhood" support, but by that time Egypt was already in the hands of pro-Saudi junta. All that Qatar could do was granting refuge to some former leaders.
Eventually the diplomatic relations were withdrawn in 2017 when KSA directly accused Qatar of terrorism support. Just about the time the USA army were assaulting Raqqa and ISIS was on the verge of total ruin.
So what about Qatar/ISIS in 2014-2017? As they started fighting against KSA/Al-Qaeda, the USA being KSA's closest ally supported Al-Qaeda and chose ISIS as their (official) primary target in the Middle East. The same was done by different satellite countries of NATO for obvious reasons. Also, Syria, Iran/Hezbollah and Russia (starting from 2015) fought against both KSA- and Qatar-sponsored terrorists including ISIS.
But it's not true that everyone was against ISIS. For example, Turkey supported Qatar in their diplomatic conflict with KSA. And also Turkey was ISIS' major trade partner. When Russia started its Syrian campaign one of the main targets was Turkey-Iraq border where ISIS transported oil in huge volumes. On 24th November Turkish F-16 attacked Russian Su-24 to protect ISIS trade routes. To follow some of "turkish events", there was deep diplomatic crysis between Russia and Turkey until in 2016 pro-USA putschists tried to overthrow turkish president Erdogan.
So even though ISIS has (mostly?) gone, the states still exist and have their coalitions and wars. For example, in Libya Turkey-Qatar-Italy still fight their proxy war against KSA-UAE-Egypt-France and so on.