If you need the original OTA update file (ZIP) for manual installation, search on ("OPPO F5 Oreo OTA") — official OPPO links are dead, but community mirrors may exist.
Comprehensive Report on the Android 8.0 (Oreo) Update for OPPO F5 oppo f5 android 80 oreo update
Initially, yes. The first 48 hours after any major update involve background re-optimization. Let it settle for two days. If the drain persists, perform a factory reset. If you need the original OTA update file
The F5 is powered by a MediaTek Helio P23 processor. Historically, MediaTek‑based devices have often received slower or fewer major OS upgrades compared to Qualcomm‑powered models. Chipset drivers and proprietary software components need to be updated for each new Android version, and MediaTek’s support window for the Helio P23 may have been limited. oppo f5 android 80 oreo update