According to a paper on the subject (Norris et. al., "Unexpected Circular Radio Objects at High Galactic Latitude" 26 June 2020), they still could conceivably be distant Wolf-Rayet star explosion. While equably conceivable to be a galaxy, possibly a new type, the paper was unable to successfully conclude it was anything other than a new type of radio-astronomical object, though they also stated it was possble that they "may have more than one type of object represented in the class of ORCs".

I hedged on possible star activity, due to the close resemblance to a nova - again, based off of my limited knowledge of astronomy. If there's another paper leaning towards the galactic end of scale, I'd love to see it - we don't get new developments in astrophysics in the news often enough.