That's probably because of faulty equipment or poor training or downright crookedness of the staff 😡.
A quarter of all FASTags lanes at 95 fee plazas on Indian highways will operate as hybrid lanes — cash plus FASTag — till March 14, 2020, Road Transport minister Nitin Gadkari said in Parliament yesterday. Earlier, 65 fee plazas were allowed to have 25% hybrid lanes from January 15, but this was extended to 30 more fee plazas on last month, he said. Gadkari did not reveal which toll plazas have been allowed to have hybrid lanes.