[fauXGT]

The flasher module only looks for a completed circuit connection, then will flash until circuit goes open. You are correct changing the flasher mod to electronic control.
Analog flashers will rapid flash with a lack of a full bulb load, indicating a dead incandescent bulb somewhere. LEDs have a fraction of the current draw, so electronic flasher needed. You can see it with ricky racers that change the bulbs to LED but leave the stock flasher in. A total rapid speed flash.
I still think it's odd that your turns work fine, but no hazard. A seperate hazard circuit in your case, maybe.