Here in our area they do lose leaves because of our cold winters in past have noticed when i had juvenile plants they were quite stubborn and they would hang on much longer than the adults but eventually drop . Yours not growing or doing anything is ok from the looks of last couple of pictures where those little buds will get greener and eventually plant will start growing again.

As a note some of mine get leaves like that from very late in season just before going dormant due to so much moisture in the air and much less of everything else sun heat etc. Some seasons when much rain before going dormant the leaves can look similar and then turn blackish following season plant was fine.

Martin

You might find some helpful information in this post about how to treat brown spots on your tree. I hope this is helpful for you! How to Treat Brown Spots on Fiddle Leaf Fig Leaves