Nokia Lumia 1020 whatsapp problem - can't download video and bugs

I am facing lots of trouble with Nokia Lumia 1020 phone but only with whatsapp has many bugs in it. Msgs are delivered quite late, whatsapp videos cant be downloaded nor it can be forwarded to anyone else. This is just a negative point. Everything else is advance level is best of best, But then why is 1020 lagging in such basic things ?? Any1 with the solution to this problem ? Plz let me know as soon as possible. I am very much feeling disappointed after spending so much money and finding such little things not there.

I think it is because windows OS won't let you save online video and same applies to Whatsapp video, you can only stream but you can't save them.

I am using lumia 625.. I can recieve videos on whatapp and send the same to other members but option for downloading and sending other videos is not there... but I still love this cell very much...

Good to know you are using Nokia Lumia 625 , so you are a windows phone 8 user.