You should never cross underfloor heating cables. This post will link you to some solutions for avoiding heating cable crossing.
The Warmup DCM-PRO Cable is a custom designed cable compatible with all uncoupling membranes. It can be installed at 2, 3 or 4 pegs. The cable itself allows primary heating thanks to the twin-core ETFE cable, for highest output. It is guaranteed 30-years. Even better results when used with Warmup 4iE Smart WiFi programmable thermostat.