I have tried a few things, heal lifts, boot stretching. The boots are a close fit but nothing out out of the ordinary fitted by a good fitter. It's not the first time I've had this problem I will get it on a bigger sized boot also.
The problem appears in either foot after about 20 mins even with the boots not done up, liners worn on their own are fine. Tight calfs high instep and high arches probably don't help. Apart from stretching more and more I'm running out of ideas ....... Thanks for any help.