Were Assemblies in Asia Still Observing Pasakh on the Fourteenth Day Long Before Constantine?

Period: 2nd century CE · Witness: Eusebius, Ecclesiastical History 5.23

What the ancient record says

Yes. Eusebius describes a major dispute over the Pasakh date; the assemblies throughout Asia followed an older tradition, the fourteenth day of the moon, corresponding to the Pasakh date in the earlier instructions; they claimed inherited precedent, not a random date.

Not every assembly agreed (hence the controversy), others followed a practice connected with the first day of the week; by the late 2nd century different patterns existed, disproving any claim that everyone always observed the same later Pasakh system. Predates Constantine (4th century) / Nicaea 325 CE by well over a century.

Development: older fourteenth-day observance, then other assemblies differ, then conflict, then Rome attempts conformity, then centuries later imperial power enters, very different from "everybody celebrated the same until Constantine changed it."