I had actually feedbacked this and my post is disregarded. I had also prove of video showing it. But anyway, I will repost it again:
The -900 variant is different from the -1000 in terms of flaps retraction and deployment timing. -900 is usually faster in deployment and retraction than the -1000.
For your product, the -900 version is as slow as -1000.
I can't make a video at sim but I can roughly provide the timing of -900.
Inbuild A350-900 Flaps 0 to Flaps 1+F = About 20 to 22 seconds
Real life A350-900 Flaps 0 to Flaps 1+F = About 10 to 13 seconds https://youtu.be/E80qj1C3rDM?t=272
Inbuild A350-900 Flaps 1+F Full 0 0 = About 20 to 22 seconds
Real life A350-900 Flaps 1+F Full 0 = About 8 to 10 seconds https://youtu.be/E80qj1C3rDM?t=1001
Inbuild A350-900 Flaps Full to Flaps 0 = About 31 to 33 seconds
Real life A350-900 Flaps Full to Flaps 0 = About 19 to 21 seconds https://youtu.be/KtKqg1tOjYo?t=754
Is just that the -900 variant need adjustments. The -1000 variant is pretty fine.