Maybe I am not understanding your problem, but I think mine behaves the same way. My warning light is flashing before engine start, indicating low oil pressure, as it is designed to do. I can press the “NEXT/Ack” button and the light will turn to steady on until I have oil pressure on start up. See manual:
The Alarms – The most important part! The instrument's alarm function will alert you to out-of-limit conditions by flashing the warning light (to get your attention), and simultaneously changing pages to a labeled screen and flashing the reading above its label to identify it. If the problem can not be fixed immediately, the alarm should be acknowledged by pressing the “Next/Ack” button on the EIS. (When the alarm light is flashing, the instrument will ignore the other buttons.) Acknowledging an alarm returns the instrument to the page it was previously on, and allows it to alert you to the next problem. After acknowledging an alarm, the warning light will remain continuously on as long as any out-of-limit condition exists. The warning light will go out when everything is within limits. An alarm that goes away, and then returns, is treated as a new warning, and will again generate the response described here. Multiple alarms are presented according to priority, one at a time.
On my installation, the only limit I monitor on the EIS is oil pressure. All other limits are configured through my Horizon EFIS. My EIS box is hidden behind the panel on a hinge that allows me to pull a push pin and swing it down below the panel for viewing if needed. I can easily reach the “Acknowledge” button before engine start to change the light to steady. If you still have a flashing warning light after acknowledging all limit exceedances, that doesn’t seem right and you may have an issue.