The failure at accelerated conditions is not too concerning, but the subsequent failure at intermediate begins to show that there is a potential vulnerability for this product. Ultimately, it’s either the packaging, elevated temperatures or both. Fortunately, the “WHO Technical Report Series, No. 953, 2009 – Annex 2” gives very clear expectations on this situation. Appendix 3, table 2 gives some label statements that should be considered–this is likely the primary justifying action you need. Also, if there is any hint of a similar trend at long-term conditions, even though one batch conformed through shelf-life you make sure you don’t need to shorten the shelf-life as a precaution. Finally, it seems to me like you likely have a weakness in packaging and should consider finding a more robust alternative as a possible post-approval change.