Can’t use the app for free anymore

I've used the Lightroom free app for IOS for quite a lot of time and it worked perfectly until a few days ago. Every time I try to click on any function of the app (even the basic ones like light or colors) a screen regarding the premium functions opens, preventing me from using any of the free functions of the app... is it normal? Even if I close it whenever I click another button it opens again. Do I have to pay the monthly subscription to use any function of the app?