Experiencing Internet Issues After Installing Snapchat

I've been having serious internet connectivity problems on my phone ever since I installed Snapchat from the Play Store. The internet only works in short bursts, both on Wi-Fi and 5G. No other devices on my Wi-Fi are having issues. My WhatsApp messages can take up to 10 seconds to send, and receiving them is delayed by over 30 seconds—my Wi-Fi watch gets them before my phone does. Notifications are also delayed, and overall internet speeds have slowed significantly. Sometimes, my Wi-Fi shows 'Connected, No internet'. It seems to improve a bit when I connect to AdGuard. I can't use certain apps like COD Mobile, which require a stable connection, and Instagram is often stuck when my Wi-Fi loses internet access. I still have 10GB+ of internal storage free, so that's not the problem. I can't shake the feeling that the Snapchat app messed with my phone somehow. Even after uninstalling Snapchat and restarting my phone several times, the issues persist. I've run SDMaid and Malwarebytes to check for anything suspicious, but nothing came up. Unfortunately, I can't reset my phone due to work-related data and apps being set up.