Dear Val, connection problems are not initiated by the used phone or tablet. They only offer the GUI (graphic user interface). It must be something between your remote and your drone.
For ECdrone:
I own this very stable tablet and phone holder. See pics for how it works.
https://www.amazon.de/gp/product/B07YZD43WC/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1
Check this: Amazon.com: iEago RC Micro USB to Micro USB Data Cable 11.41 inch Nylon Braided Right Angle Connector OTG Cord for DJI Mavic Pro/Spark/Mavic Air/Mini/Mavic 2 Pro & Zoom Accessories.: Industrial & Scientific
Works for me.