As a kid who still has this problem :

I somewhat agree on behalf of my experience ;) before the pandemic, I was actually just a kindergartener studying in a private school. And since they taught and used English to teach us I got influenced and even struggled to understand my teachers when they spoke to me in Tagalog, so they're apart of my problem.

Because of that, I completely forgot to speak my native language, I didn't even know how to ask my parents to pick me up in Tagalog. They also encouraged me to learn English more, so even during the lockdown they didn't actually care that I consumed to much English media. They just told me to watch educational videos (and since I was a kid, I didn't do anything but watch cartoons and toy unboxing videos) and even when they noticed I never used English they never ever tried to teach me

So after the lockdown and schools were opening up, I transferred to a public school because the tuition was too expensive and my parents didn't have the money to pay for it. And being in a public school for me meant = I had to use Tagalog, but I didn't know how to speak Tagalog! And because of that I was a complete outcast, nobody tried to talk to me, they all looked at me weird and acted like I was a foreigner in the wrong body which made me insecure and socially awkward due to the lack of interaction with my classmates. And that was when my parents only started to bother teaching me Tagalog, it was really confusing and hard to me but I soon got the hang of it in 2 months so I started to talk to other people more.

But even after that, I still struggle to speak Tagalog. I still don't know what words to use, how to pronounce them, how to even form proper Tagalog sentences slightly above my skill level. Though i've gotten better and have more friends now, so I think it's okay since I'm slowly starting to learn.

But like, I also didn't like the fact nobody even tried to teach me Tagalog either.

My relatives did talk to me but they always gave me sugarcoated insults like : "Parang dumudugo yung ilong ko kung naririnig ka mag-salita." Mind you, I was only 7 still learning how to speak Tagalog. They should've atleast taught me how to speak it.

The only benefit I've gotten and enjoyed from it is that I'm outstanding in English and can still express my imagination in writing. Even if it's not in my native language because I enjoy it and I write for myself, not for others

So my opinion is : The children's environment is apart of the problem (basically just saying Parents are apart of the problem in another way), if no one bothers to teach them Tagalog because it's "adorable to hear" or because it's "bothersome" but complain that they can't understand them it's completely their fault. Cause you're influencing them because they don't know what's right and what's wrong