Yes, testing could definitely be better. With every change, there is a chance it breaks something else. They apparently thought they improved the performance, it’s even in the patch notes. Maybe that change had a side-effect they did not anticipate. There are also bugs in other new features they added (quick play map selection, dequeuing from global queue).
A mod on this forum suggested they should release a beta version first:
Turns out that wouldn’t have been a bad idea.