First, I'll start off that a brief several searches for "timer" and similar revealed nothing even close to this. Second, I have no proof or way to "show" this bug.
During PVP Duel, with recent games in the match going very smooth, my turn-timer began to start at lower and lower values on the beginnning of my turns. I first noticed when I did not finish actions in a time I usually 'feel' sufficient to avoid timeout. A second instance of this and then I watched the timer - 40 seconds on it at the very beginning of my turn. In attempting to mention this and bring it up in chat (to track the problem during the event match/duel) I did miss hitting the end-turn timer here. Next turn was even lower in the 30's. A few turns like that and then sub-30 second timers quickly winding down to 1-second turn timers. The total match was 13 turns according to the post-game summary Elements gave me...
Finally, I post this here mostly in case it comes up in the future there can begin to be a record of frequency etc.