Non-monotonous temperature variation of the magnetization relaxation rate in YBCO films with BZO nanorods below the matching field

► Vortex depinning temperature in YBCO films with BZO nanorods remains close to Tc. ► This is in agreement with the classic Bose glass theory. ► The S(T) maximum at low T is due to the occurrence of thermo-magnetic instabilities.