While OxygenOS 4.5.3 is a global roll out, Oxygen OS 4.5.4 is a region specific update. Currently, the update is rolling out for Netherlands users for fixing 4G LTE network issue. Oxygen OS 4.5.4 OTA update just weighs around 18MB and all affected OnePlus 5 users will get the OTA (over the air) update in the coming days.
Yesterday, OnePlus rolled out OxygenOS 4.5.3 update for OnePlus 5 with fix for Wi-Fi drop issues, Google Translate issue, and optimization for system stability, camera, auto-brightness, etc. The OxygenOS 4.5.3 rolls out was global, and if you have not received the update yet, check it by going to Settings > System updates > check for updates. Alternatively, check out this guide to know how to update manually. As mentioned above, Oxygen OS 4.5.4 update is for Netherlands and some other parts of Europe. If you are experiencing 4G LTE issue on your OnePlus 5 and did not received the OTA you notification yet, check it by going to Settings > System updates > check for updates. (Source – OnePlus)