Flux ratio between GLOSTAR and CORNISH as a function of the GLOSTAR spectral index at 4–8 GHz of the 86 sources, including 38 variables (black dots) with |f_var| > 30% and the remaining 48 sources (gray dots) with |f_var| < 30%, as defined in Sect. 3. The purple shaded area includes the variables with flux increase and the green shaded area includes the variables with flux decrease, as outlined in Figure 2. The red circles display the Top7 variable UC H II region (see Sect. 4.1 for details), six of which have reliable spectral indices listed in Table 1.