A bit of checking/cracking is normal and part of log made art.
They may open and close depending on the weather and time of season.

We apply wood sealer to our carvings to help protect them from the weather elements and slow down the drying process to help reduce checking/cracking.

An ideal location is a shaded area or a covered porch.

Direct sun or a location near a heat source can increase checking/cracking.

Maintain air flow beneath the bottom of the carving using rocks, bricks, furniture slides, rubber feet, etc.

We would recommend brushing a coat of sealer on annually as well as an  additional coat or two of wood sealer (poly/spar urethane) if you notice checking or water no longer beading off the surface.