We’ll need to know more information about your office and gym cards. You can scan them with the TagInfo app (also from NXP) and post the info here. Refer to this post on how to share TagInfo scans. Make sure to censor any sensitive information, like the UID under “Detailed protocol information”
If you can’t scan them with any apps on your phone, it’s possible (though not guaranteed) that they’re Low Frequency cards. If that’s the case you’ll need more a NExT or xEM and more advanced tools to clone them.