Timelapse Premier Pro not working as it should !

Hi there, 

firstly i am a newbie to premier pro, i have the latest version and have followed what i would believe to be the right steps and imported from the opening page by clicking the first of a list of photo files in tiff format and they do all import as pictures and they do not sequence although the sequence button is pressed. ! therefore i have a jolt every clip. 

Please can somebody guide me! none of the videos online on this topic are up to date with the latest software thank you and apologies if this is a stupid question ! it did work before a few weeks ago ! 

The photos are in TIFF - they have been edited in lightroom and exported as the edited TIFF files and all the number sequencig is as Lr exports. NOt sure what else it could be sorry !