Alright, during the entire thing I've noticed a pattern.
Not sure about brownish with red tint (the camera makes it look like really bad, but it doesn't look
that bad IRL. Still something to consider), but one certain thing is that the stool is consistently at least a bit yellow. I was suspecting it might be the Tabernil total oral solucion medicine since it is yellow and makes the water color like so (my bird glady drinks it and doesn't suspect anything LOL).
What I've found in my research is that is it could be the medicine causing it, especially ones having high amounts of Vitamin A. At least the medications will only be for a limited time, hopefully. Wouldn't want to put my bird on unbalanced amount of vitamins forever... so I'll be skeptical and get a second opinion if the current vet asks for more time on this medication. Gosh, why didn't I just go to the vet that treated my bird's eye injury in the first place? I think I would've been more at ease. I'll find a time to message the other vet about this, and see what they think.
This page on the official website says that the Tabernil total is a vitamin supplement, so the fact that my vet also mentioned that if my bird is getting enough calcium makes me think....
And the timeframe is "during 5 consecutive days, twice a month" (10 total days in a month?)
But to fair it states "To enhance the bird's general health and during and after any infectious or parasitic disease" and "After long treatments with sulphonamides and antibiotics", though I am genuinely not sure if I would call 7 days (5 consecutive, then one day without, then 2 more days like vet asked) of gentamacina "long". I guess let's consider that it makes it a bit more than
this page's recommended range of 3-5 consecutive days?
In conclusion, I'm only a bit less worried about my bird now since seeds and bubbles, maybe stringy stools too now appear at rare inconsistent times, but I am still feeling a bit so-so about my bird...
I wonder if the other vet still remembers me and my bird. I have went there with my sister because she scheduled a checkup for her cat at the same time too (you might guess how the eye injury happened

). She took her cat there... a lot. (yeah early death of the cat was imminent

. It was a Scottish Fold after all (Scottish Straight to be more exact but same thing just no floppy ears), so they are usually unhealthy... but it was still wayyy under expected age of 15).
The passing of my sister's cat made me look after the bird more, and pretty much right after that I think I have just caught seeds and bubbles in stool early, have never seen them before. It was a matter of time honestly as I have not taken my bird to a vet in a while.
I wonder.... why did she recommend me this vet though? Her last visit was the previous one that I mentioned... so I believe she only took her cat to my current one for grooming since I've heard they're good at that. Wonder what was her thought process... I should stop being hesitant and ask.
But I digress, enough about past cat. Let's focus on my bird for now.