I can import a PTE file from PTE 8 which has a modified interval time and it works perfectly in PTE 9 and the "interval" is properly displayed.
If I attempt to change the interval on an animated gif in PTE 9, it reverts to the original every time.
The fact that it works properly when imported from PTE 8 means it's "possible" to have the interval changed from the default of the original animated gif when playing in PTE 9, but any changes made to the interval in PTE 9 will absolutely not "stick" it continually reverts to the original interval.
Best regards,
Lin