Two) were they ever seen by IFTTT before? That is, is this a new problem?
If it’s not a “ used to work, stopped working“ problem, open the app and make sure that all the sensors you want to use are authorized for the IFTTT integration:
Three) IFTTT Integration is a single level if/then construct, so you will only be able to trigger off of one device at a time. Is that the issue you’ve run into? If so, you can’t fix it from IFTTT, but you can use a different logic method with SmartThings. See the community FAQ (the thread title is a clickable link)
what version of the SmartThings mobile app are you using?