Answer from my broker. Maybe of interest to others:

I see your orders for SRGE. Apex does have restrictions on the amount of shares you can trade of a stock at one time. They allow you to trade up to 10% of the past 20 days volume. The orders you placed were rejected at the route directly. It was most likely rejected because of the amount of shares being greater than the 10%. You can usually bypass that limitation by routing directly to a market maker who makes a market in otcbb or pinksheet stocks. You can try to route to CSTI. Please also be aware that if you do trade more than the 10% average you can be subject to the illiquid fine from Apex which is $250 per day. By routing away from Apex, you may be filled, but you are still liable for that fee if you exceed the 10%.