I made a mistake...I mean in normal scan(YT, not ROLL)...timebase slower than 100mS does not show picture till end of scan....example...you have a slow changing signal that needs timebase 50s, 14div x 50s=700s.You are without trace till end of scan, 700seconds!!!..this is really bad news...I hope they will solve that...
This does not sound like a bug but rather a by-product of delay caused by filling the buffer pre-trigger. Can't you just move the trigger position left (i.e. earlier in the buffer) to eliminate the delay?
Can not call bug. (If think that bug is thing where someone have programmed something and it do not work as he think he have write it)
This is other kind of "bug". This is "bug" in design in latest official public FW. (this I can confirm because I remember this detail well)
Before trigger position, this delay can not remove. It need acquire pretrig buffer area until trigger time position. After trigged and possible fine adjusted it can push it to display and continue visible acquiring until trace ends.
If it works like this, then if user set example trigger time position to left border of display (even to zero pre trigger buffer) he can see continuous draw*) just after it first time have find trigger event. If there is continuous signal there can now see continuous visible trace update even if there is 50s/div selected - if want sit and look.
*) just like analog scope with extremely low horz speed and CRT memory (or very long persistence) on.
Just check that this is exactly how Rigol 1000Z works with very low horizontal speeds. After it finds trigger event it show pre trigger trace and continue visible acquiring.