The electromagnetic field of a bunch moving through a vacuum gap located in a dielectric loaded waveguide is under investigation. This paper focuses on the case when Cherenkov radiation is generated in the dielectric parts of the waveguide. Analysis of the field components of the waveguide mode is performed both analytically and numerically, and the electromagnetic field structure for different time moments and different gap lengths is demonstrated. In particular, it is shown that for dielectrics with permittivity ε <2, the field of the ultrarelativistic bunch can be restored in the area after the vacuum gap for some optimal parameters of the problem. However, for dielectrics with ε > 2, restoration of the wakefield can only be realized for small lengths of the gap.