@sheepwash i mentioned my issue the other day. ASX a horrible...

@sheepwash i mentioned my issue the other day. ASX a horrible system. I too did the same re ComSec.

After phoning around (not even my broker could answer) I was pretty much told, you put your offer in on whichever platform, then they talk to each other. Wherever the least affect on market price will be taken. Ie. I tried to wipe 2.5c line last week. That was next best market offer. Not according to chi x. There was a 2.4 (which coincidentally was not there when I placed my order). Then no trades showed on ComSec. It still showed sp at 2c. I was annoyed.
At the end of the day, the platforms amalgamate and you should get an indicative after all trades are matched. This is that 4-4:30pm window. If no other trades occurred, we should have seen 2.4c on ComSec at EOT.
It's honestly a crock. I believe (not substantiated) that if a trade is going to push the price further up than let's say 10%, the broker (ComSec) will search the alternate platform (chi x). I would not be surprised if some 'SIs' are contacted or other parties like 'bergen' who are contacted or have triggers set for above market orders.
Again, there should not be a seperate 'market/platform' it's a perfect way to confuse and therefor make trading hazy. ASX vs chi x, it doesn't make sense - outcome achieved. It's not supposed to.