Facebook In-app browser issue - Session cleared?

Hello! Let me please first introduce you the project we're about to release: http://www.foundspot.com The project is aimed to freely help people to find the objets they've lost or to contact the onwer of what they've found Project has been developed in Laravel by a vendor.

We've now seen an issue happening on FB in-app broswer. If the page (www.foundspot.com) is open inside fb app, we're not able to pass from http://www.foundspot.com/es/step1 to http://www.foundspot.com/es/step2 as it gets directly to landing page.

To me this seems like a not well handled session problem but according to vendor this is only FB app to blame. One more argument to my "lack of trust" is that it is only happening on android FB app ,not in iOS

Unfortunatelly im not yet used to laravel to quickly fix this + i dont have the time to invest in a short-term laravel learn. Would anyone suggest what to check or to provide or if this is known to really be only Fb issue Thank you in advance