Wow Im glad u got that figured out and taken care of. I hope thats not the case with my bird. The vet had already sent his poop sample in to get tested and all they found was 2 types of bacteria in it. Wouldn’t the test have detected if it was chlamydia?I'm wishing you luck with your new veterinarian.
The only time my budgies poop have been abnormal is when I accepted an escape budgie who's owner wasn't found. That brought chlamydia into my flock and all my birds got sick( some life-threatening)
Their poops looked a little like yours , but did have the classic bright green urine if chlamydia. It took 45 days of doxy , then a relapse and 45 more dsys of doxycycline to clear.
It could be chlamydia is a possibility with yours. Other antibiotics can temporarily make it seem better if it is this. But to cure them takes the extended doxycycline. We ended up going the added to water route for the budgies. And its important to treat the whole flock. And extensive cleaning, my vet had me spray dilute bleach before cleaning to minimize aerosol .
Anyway I hope answers are found .I will watch your thread