MixPad dropping every few tens of seconds

Running this linked setup for a special at church this morning.
The Qu is the normal church mixer, with 4 local Ch38 wireless mics plus 2 x AB168 stage boxes. The SQ5 is mine. Alternative setup AB boxes into SLink port of SQ, SLink card in I/O port to DLink port of QU. SQ Clocked from QU via I/O port, Absolutely no audio issues !!
WiFi access (antennae just visible behind QU) perfect! (5gHz)
Mixers net ports linked via Netgear switch taken straight out of my working home network, ie no known problem!
Qu Pad works perfectly!
SQ MixPad (V 1.6.1 for pad and mixer!) drops after about 15 SECONDS
EDIT
The mixer is V 1.6.2 firmware

2nd EDIT
After testing with just windows laptop connected direct to mixer, and getting exactly same problem backdated firmware to V1.6.1 worked perfectly!
Reconnected via WiFi and with QU also on network still perfect.
Ergo there is an issue with V1.6.2 or I managed to do a duff upgrade, either way, I don’t care I have a working remote capability for Sunday!*

What happens if you disconnect the QU from the router?

How are both mixers set for IP addressing?

After service I connected SQ direct to WiFi hub, which is set as DHCP master, and checked nothing, other than my iPad was also connected by running IP scan on network, only 3 items, hub, mixer and iPad. Exactly the same result.

SQ is set to DHCP, (192.168.0.199 given address)
QU set to fixed 192.168.0.200
Both subnet 255.255.255.0
Gateway/ DHCP master 192.168.0.254 ie the wireless hub
I must be missing something, or my update to firmware, which was forced by all my iPads being V1.6.0 or higher and mixer being at 1.5.x, can’t remember last figure, but that is irrelevant, is corrupt!

FYI I have been using multiple A&H mixers on common networks, for over 10 years, including my home network which has SQ Rack, AHM64 and AHM16, along with 21 other devices, including 2 wireless APs and 7 Dante devices, 3 of which are the A&H mixers and 2 are Bome Boxes for MIDI control. So I am not a novice at using network, just confused by this particular one!

Just sitting at home in my sitting room, with 3 versions of MixPad connected to my SQ Rack, there are 35 other items on the network, no seperate LAN just a 16 port and a 24 port switch. The mixer is running V1.6.1 not 1.6.2 which is what my SQ5 has. I cannot do anything today in church, but tomorrow, I shall step back to 1.6.1 on SQ5 and see what happens.
Actually one Android pad is running Mixing Station, but still prove the system here is stable, whereas my SQ5 with V1.6.2 is not

I have the sme dropouts on 1.6.1. Ipad and sq on a tp link mobile router. Didn’t have issues before. I suspect the router is somehow overloaded. It worked fine when i replaced the tplink with an apple access point at the same gig.

I doubt MixPad would overload a router , the data rate is pretty slow , and after the service I tested with just the router, iPad and mixer , nothing else on the net, and proved that by running a network IP scan, before trying to connect MixPad, or Mixing Station. And it cannot be the router, because when it was Mixing Station that was connected, I could download the fader layers live, but not actually control them, or upload changes I made in Mixing Station. Either there is an issue with firmware 1.6.2 or a corrupted install, or something more major with my SQ5. Which other than doing the system setup on Friday, had not been used since July, when I bough my SQ Rack.
Oh and 1.6.1 on my SQ Rack runs perfectly, it is 1.6.2 on the SQ5,

Just curious, as a test, if you have bypassed the switch altogether and plugged straight into the router?