WhatsApp for Infinix Smart 8 HD

Most ads come from preinstalled Infinix apps (Palm Store, Hi Browser, Phone Master, Boomplay) showing push notifications and recommendation content. Open Settings > Notifications & status bar > App notifications (or Settings > Apps > [app] > Notifications) and turn notifications off for each of those apps. In Palm Store and Phone Master, also open the app's own Settings and disable 'recommendations'/'message notifications'. To block full-screen overlay ads, go to Settings > Apps > Special app access > Display over other apps and deny it for those apps. Long-pressing any ad notification and choosing Turn off also stops that specific source. See how others solved this on Reddit

This is usually a SIM/network setting rather than a hardware fault. Go to Settings > Mobile network > SIM cards & mobile networks, confirm the correct SIM is enabled and set as default for Data and Calls, then toggle Airplane mode on and off (or restart). If it persists, open the SIM's Access Point Names (APN) and choose Reset to default, and try Settings > System > Reset options > Reset Wi-Fi, mobile & Bluetooth to clear saved network settings. If still dead, test the SIM in another phone to rule out a carrier or SIM issue. See how others solved this on Reddit

Picture-in-picture and floating windows need an overlay/PiP permission that XOS often has off by default. Go to Settings > Apps > Special app access > Display over other apps and enable it for the app you want (and check Picture-in-picture in the same Special app access menu for apps like YouTube). Then disable battery optimization for that app via Settings > Apps > [app] > Battery > No restrictions (or Unrestricted), because aggressive XOS power saving closes background overlays. See how others solved this on Reddit

XOS battery saving freezes WhatsApp in the background so calls never ring. Open Settings > Apps > WhatsApp > Battery and set it to No restrictions / Unrestricted (allow background activity), and turn off any Power Saving / Smart power mode in Settings > Battery. Then check Settings > Apps > WhatsApp > Notifications and confirm the Calls channel is on with sound and set to pop on screen. Locking WhatsApp in the recent-apps tray so the system doesn't clear it also helps. See how others solved this on Reddit

The Smart 8 HD ships with only 3GB RAM, so heavy multitasking plus bloatware drags it down. Disable or uninstall preloaded extras (Boomplay, Palm Store, Phone Master) via Settings > Apps, enable the Memory Fusion / extended RAM feature if your build has it under Settings > Special features (or Settings > Memory Fusion), and keep storage from filling up. Limiting background apps and reducing animation scale in Developer options also gives a noticeable boost on this low-RAM model. See how others solved this on Reddit

They are close: both are entry-level phones with similar HD+ screens and modest RAM, so for everyday WhatsApp, calls and browsing you won't feel a big jump. The Smart 9 mainly brings a newer chipset and updated Android, but if your Smart 8 HD already runs your apps fine the upgrade isn't essential. If performance is your real concern, put the money toward a model with more RAM and storage instead. See how others solved this on Reddit