extra dot on a VOT XX from Thessalonica

[Victor]

Here's another example of those pesky dots that pop up. There is an extra smaller dot under the centering dot.

Constantine I
A.D. 324
18x19mm   2.6gm
CONSTAN-TINVS AVG; Laureate head
DN CONSTANTINI MAX AVG surrounding wreath enclosing VOT XX
in ex. TSAVI
RIC VII Thessalonica 123