[Ford E4OD Transmission Will Not Engage After Sitting]

My 88 bronco 2 is having the same issues aND the fluid, filter and modulator valve were changed.  Drove fine for a Lil while now back to square one.  Cranks up fine but will not engage in any gear

[Ford E4OD Automatic Transmission Shifting Issue]

1988 ford bronco 2 4x4. Out of nowhere truck will not engage move after cruising 40-50. Replaced filter with new fluid and modulator valve and drove fine for few weeks before having same issue. No slipping or metal chunks when t fluid changed. Please help!