kd92jew I'm still kind of suspicious that this issue came up (after many months of successful use) after I made a trip overseas, and used an Esim and a Google voice number. That, in combination with the fact that it has GrapheneOS on it.
Well, 200,000 or so people have GrapheneOS on a Pixel, some for multiple years, and plenty of them travel overseas and use eSIMs (especially for travel, I think). If those were major risk factors I think the forum would be flooded with reports.
I have no idea how many people with GrapheneOS use Google Voice, but unless there is some indication it's risky, it seems like a low-likelihood factor.
Meanwhile, people do steal phones, and the IMEI blocking system is designed to disincentivize theft. The delay could be explained by a theft going unnoticed for a while (which happens) and/or a police report sitting on somebody's desk for a while (which also happens).
Unfortunately, I doubt your carrier will ignore the block, and I doubt Fi will lift it. Presumably the dealer you bought from paid somebody for the device; whether the dealer can get some of that money back or is willing to cut you a deal is unknown. But I doubt you will be able to get money back from whoever the dealer paid.