Are you saying that data you have put on the Seagate appears to be missing? If so you could try Recuva
By the way, looking at your profile you have never "green ticked" a question you have posed - I hope they are not still unresolved.
Huawei Mate 30 Pro Review: Hands-on
Fred Deakin on creating the artwork for his sci-fi rock opera The Lasters
Best iOS 13 features: What does iOS 13 do
Les meilleures enceintes connectées avec écran tactile (2019)