Here is the SSM from Ford, per this communication, production was clean for F-150 on 7-10-18 and Expedition/Navigator on 4-8-19. Is it possible the engines your getting are out of an Exped/Navi?
48445 - 2017-2018 F-150, 2018-2019 Expedition/Navigator - 3.5L EcoBoost - Ticking/Tappin
Some 2017-2018 F-150 vehicles built on or before 10-Jul-2018 and 2018-2019 Exped ition/Navigator vehicles built on or before 8-Apr-2019 with 3.5L EcoBoost may ex hibit tick, tap, or rattle type noises from top of engine front cover for 2-5 se conds after a cold start. Replace all 4 VCT units (6256/6C525) and update the PC M calibration. Do not replace other camshaft timing related components unless in spection identifies a concern. Refer to the Workshop Manual, Section 303-01. Cla im labor to replace VCTs using published labor operations and PCM programming us ing M-time. Dealers should order parts only when required to complete a repair. Once the parts are ordered, the vehicle may be returned to the customer to drive . This condition does not affect long term durability or performance.