DHCP assignment

> My address range the router assignes is from 192.168.0.1 to
> 192.168.0.254.

   That's the DHCP pool?  ".2" - ".254" would make more sense if the
router itself is at ".1".  Otherwise, that's plausible.

> I have two devices [...]

   Not a very detailed description.  Not detailed enough, either.

> [...] that with fixed addresses (static IPs) of 10.3.100.211 and
> 10.26.74.234. [...]

   That would present a problem, if the LAX20 LAN is "192.168.0.*".

Also, the only way that a device at "10.3.a.b" could communicate with
a device at "10.26.c.d" would be if they're using a subnet like
"10.0.0.0/8", and I would expect your LAX20 to have trouble with
any subnet mask narrower than "/24".

> [...] These addresses are indeed static within each device and cannot
> be changed.

   That's pretty hard to believe.  I can't remember ever seeing a device
with permanent/unchangeable IP parameters.  Of course, all I know about
your "these devices" is that they're apparently trouble-makers.

> [...] They are designed to be able to "talk" to each other when they
> are direct connected together or to "find" each other on a network as
> they work specifically together via ethernet.

   Also not easy to believe, as stated.

> The problem is, when either of these devices are powered on and take
> their static IP addresses in the router, any device that connects to the
> router AFTER doesn't get assigned an IP address in the range of
> 192168.0.1 to 192.168.0.254. [...]

   The simple explanation for that would be that at least one of your
(unspecified) "these devices" is running its own DHCP server, and your
"any device that connect" is getting its IP parameters from a DHCP
server other than the one in your LAX20.  Running multiple,
uncoordinated DHCP servers on one LAN segment is an invitation to
disaster.  And, apparently, someone accepted your invitation.

> [...] Currently, I have one such device attached and it is receiving a
> dynamically served address of 10.22.0.57 from the router. [...]

   What leads you to believe that that address is coming "from the
router", and not from some other device?  I'd bet that the LAX20 has
nothing to do with any "10.x.y.z" address.

> [...] All LAN services are available to the device, but WAN services
> don't appear to be. [...]

   Of course not.  The LAX20 (router section) would not communicate with
devices which have IP addresses off its LAN subnet ("192.168.0.0/24"),
even if they're using the same Ethernet segment.

> My current work around [...]

   I wouldn't try to find a work-around. I'd try to configure my LAN
devices is some way which makes sense.  That is, so that they all use
the same IP subnet.

> [...] Neither of those solutions is very convenient.

   I wouldn't call either of them a "solution".

   If your (unspecified) "these devices" are really as anti-social as
you claim, then I'd look into building them their own, separate Ethernet
network, and keeping them as far away as possible from the LAX20 LAN.

Conceivably, some VLAN tagging scheme could be employed (with more
exotic network-switch/router devices), which might provide the required
logical isolation without requiring physical isolation, but arranging
that would exceed my expertise.

   In principle, the LAX20 could be configured to use "10.0.0.0/8" for
its LAN, but you'd still need to deal with the apparent (but obscure)
DHCP server which, I claim, must be running someplace (else). And, as
cautioned above, I would not expect an LAX20 to work well with a "/8"
subnet mask.

   If you expect your (unspecified) "these devices" to communicate with
devices on the LAX20 LAN, rather than ignore them, then I'd start by
looking for some actual information on your (unspecified) "these
devices", rather than what looks to me like the folklore ("fixed
addresses", "cannot be changed") upon which you currently seem to rely.