Hi Juan,
I create a project, and test it ok, it use the Init_FTM component, and configure the FTM0_CH0 and FTM0_CH1 in combine mode, make the deadtime to about 10us.
Please find my project in the attachments, it is based on the TWR-K70F120M.
The test result as follows:
Picture1:with no deadtime

Picture2:with about 10 us deadtime

Wish my answer helps you!
If you still have question, please contact with me!
Thank you and best regards!
Jing