Is there a maximum number of units you can gift ?

I'm trying to bolster the defences of a CS by gifting it units, but only the first few worked. After that, my units would disappear but vanish completely - the CS never got them. At first I thought it was because I tried to gift my UU, but it didn't work with anything...

Is there a limit on how many units you can gift ?

ive actually done this where none of my units showed on screen. i gave 3 units to a CS and none of them appeared. id like to know why that is too.

It does take and few turns and is does not work instantly...

It happened to me sometime.
I think the CS immediately sell units it cannot afford to maintain or just doesn't need.

If you gift 3 or more units at once, they dissappear. If you gift 1-2 units before the last batch has appear, they will dissappear. It's really stupid.