Most Service Ports No Longer In Stealth Mode

I too have have a Netgear product:

Nighthawk Tri-band AX8 8-Stream AX6600 WiFi 6 Router

All of my router's ports used to be in stealth mode too.

Testing was done at ShieldsUP (https://www.grc.com/shieldsup).

After applying the latest update, all of my service ports are closed but only about a dozen are in stealth mode randomly.

Router Firmware Version prior to update V1.0.15.146
Router Firmware Version after update V1.0.19.172

I have the same issue, as yet unresolved.

What gives Netgear?  There is no update on the website for router firmware (RAX 70) version V1.0.19.172.  And yet the routers' UI showed me that there was an update.

I too have this on a RAX10 with most recent firmaware.  A RAX10 with older firmware does not have this issue, what gives? I want full stealth on all ports, but its only on the first 100 or so ports.  Please fix asap. 

Thank you. 

I ALSO have this problem, Router is a Netgear Nighthawk RAX54v2. I recently have been getting TCP SYN Flooded daily, 100s of entries but none are saying if they are blocked or anything just that they happened on tons of high # ports. I've researched how to stop it for over 3 weeks and NOTHING. The router has no ability to stop it and cant make SYN cookies. Also cant even stop it with 'block services' because it only blocks LAN IPs and NOT Virtual ones.  It's HORRID and slows me down so I tried to figure out if i can HIDE from it. If i STEALTH my ports then they can't try to SYN them right? So I used GRC and... 80% of my ports are CLOSED and only a handful are STEALTHed. 

So yeah... no help from Netgear, newest farmwear is up to date and all that. Netgear NEEDS to do something about this, im tired of these floods.