Maintenance Required Light not disappearing in my Honda Accord Hybrid 2005 even after resetting many times?

I've a Honda Accord 2005 Hybrid and I got a "Maintenance Required" blinking for about 15 seconds everytime I started the car. I did an oil change from a mechanic shop and later I observed that the light still appeared. So I checked online and found how I should reset it

But even after I did that for 5 times, it still appears. I showed the issue to the Walmart Mechanics and they said that since the light doesn't stay after 15 or 20 seconds, it doesn't matter.

Should I take his advice or should I show it to another mechanic?

Added (1). JetDoc- I do get all these lights flashing when the key is at number 2 position when the battery is On and engine is still at off… When we start the engine, then all these lights do disappear but this "maint rqd" light alone keeps blinking for upto 15 seconds… While other lights are shut off

You should have all sorts of "idiot" lights flashing on your instrument panel when you first start the car. That's a NORMAL test mode to show you that all the lights are working. If they all go off within a few seconds of starting the engine, then no worries. It's only when the warning lights stay on while driving that you MAY have a problem. When in doubt, READ the owner's manual.

Get a scanner and read any codes.

Are you going to believe everything you see on You Tube? Get the owners manual out and read what you need to do for your vehicle.