It depends on the kernel version and the s905x4 SOC revision.
some speculation:
the older s905x4 rev b SOC doesn’t have this problem on kernel 4.9. Amlogic made some change to the newer s905x4 rev d, and updated their kernel 5.4 decoder code to account for the change, but didn’t backport it to kernel 4.9.
The s905x4 only very briefly ran on kernel 4.9 (Android10) before kernel 5.4 support was added (Android11). Most of the lifespan of the s905x4 has been using kernel 5.4, where it has the most support including CE-NE (kernel 5.4).
Presumably no s905x4 rev d boxes were ever released with Android 10 (kernel 4.9) for Amlogic to have needed to address this problem.
No CE-NE doesn’t support DV FEL, Amlogic dropped FEL support in kernel 5.4.