Siglent SVA1032X - Odd Full Span Sweep Time

[NY2KW]

I noticed an odd thing with my SVA1032X.  If I set it to factory Preset and time the full span sweep with BW at 1MHz, it takes about 0.5sec 
At 300kHz sweep time is ~ 1.5 sec
At 100kHz sweep time is ~5 sec
At 10kHz sweep time is ~8 sec
BUT at 30 kHz it takes 30 secs.  Shouldn’t the sweep time fall somewhere between the 100kHz and 10kHZ?

Nothing else changed except BW.  Can anyone verify if they see the same thing or offer explanation?

Jerry