I suspect if it was the med, it would have started earlier than this, normally as you make the dose change. If it had come & gone since then, I would be thinking it was the med. But given there was a 4 month gap, it does seem more likely it's about your anxiety.

I've found with my anxiety that I have had many passing phases where some symptoms have cropped up & gone again whereas I have some symptoms which have remained all the way through.

I guess we have to remember that just like how someone with depression has thse various phases, so do we. Sometimes we are hit with fatigue or lack of motivation and they impact other areas without us realising.

There is no evidence this is going to be a long term thing for you so I would just see how you go. Changing meds if you don't need them, and if they are helping you in other ways, isn't something I would do until I had enough evidence I really needed to address it.