Lot of riots got "declared" here in Seattle too, usually after the cops rushed a stationary peaceful group, and many breakdowns of projectiles and aggression by protestors were publicized by police. But a huge amount of it turned out to be fabricated, exaggerated, or embellished.

These were not fabricated events in Portland. In fact the mayor restricted what the police could do and how far things had to escalate before the police could do anything. Lasers, fireworks, fires, bricks...not much was off limits to the rioters every single night for months. You can claim the group was stationary and peaceful...but there were agitators mixed in and causing problems. There are tons of videos showing the violent tactics being used by rioters...but usually the only ones to make the MSM are when the police responded. Antifa...yes they exist...were well organized and restricted journalists from documenting everything unless they wanted them to. Even the local news reporters were harassed and assaulted by them.

There were also instances found where the agitators turned out to be agents provocateurs.

Source? I have not seen any confirmed incidents of agent provocateurs. The news would have went batshit crazy if such a thing was actually confirmed.

A crazy city council member claimed fires were started by cops in Portland...without evidence and despite contrary evidence showing them being started by the protestors/rioters.

You see the bias inherent in trusting the police on this issue though, right? It's in their best interests to declare any protest against them a riot because it excuses more violent actions on their parts.

There were more than 120 days of protests detailed in the above link, only about 25% of which were classified as riots. There were live streams from these protests and riots every night, many of which include numerous incidents of explosives being hurled at police and fired being lit. Its not an issue of trust - the hundreds of archived videos containing thousands of hours of live footage of these many protests and riots is easily available to anyone who wants to examine the proof with their own eyes. This isn't an issue of ideology, its a matter of documented history and objective reality. One can argue about whether the riots were justified or not, but not over whether they happened - they did.