I have no idea why that would correct the issue, but since it's not falsing now that's great. Of the three FT coils for the Greek platform detectors I've used, I like that 8" round the best. Hope you find a lot of goodies with it!
The Eurotek was ahead of it's time when it came out in 2013, the ability to turn down the volume on the ferrous while keeping the non-ferrous at full volume is a feature I really like that other detectors have incorporated since. I like to hear it all but have the ferrous volume way down so a volume setting of 11 is ideal for me.