I think I might be seeing the problem that Geinian was trying to describe.
I was able to connect web interface on the openevse network (192.168.4.1). At this point I told the openevse to connect to my wifi network where it was given the IP address 192.168.1.142 (confirmed on the access point list of wifi clients)
I then tried to point a web browser at http://192.168.1.142 and got nothing. I have done a tcp dump of the network interface to see what is happening, and the openevse acks the browser get request but does not return any data (see below) The openevse then trys to resets the tcp connection. If I force openevse back to advertising its own network by turning off my access point then I can connect to the web interface just fine.
21:47:20.572894 IP 192.168.1.104.38780 > 192.168.1.142.80: Flags [S], seq 1673826079, win 29200, options [mss 1460,sackOK,TS val 764089525 ecr 0,nop,wscale 7], length 0
E..<."@.@..R...h.....|.Pc.........r..u.........
-...........
21:47:20.578662 IP 192.168.1.142.80 > 192.168.1.104.38780: Flags [S.], seq 326816, ack 1673826080, win 5840, options [mss 1360], length 0
E..,...............h.P.|....c.. `...v......P..
21:47:20.578732 IP 192.168.1.104.38780 > 192.168.1.142.80: Flags [.], ack 1, win 29200, length 0
E..(.#@.@..e...h.....|.Pc.. ....P.r..a..
21:47:20.578983 IP 192.168.1.104.38780 > 192.168.1.142.80: Flags [P.], seq 1:322, ack 1, win 29200, length 321: HTTP: GET / HTTP/1.1
E..i.$@.@..#...h.....|.Pc.. ....P.r.....GET / HTTP/1.1
Host: 192.168.1.142
User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:69.0) Gecko/20100101 Firefox/69.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Connection: keep-alive
Upgrade-Insecure-Requests: 1
21:47:20.648402 IP 192.168.1.142.80 > 192.168.1.104.38780: Flags [.], ack 322, win 5519, length 0
E..(...............h.P.|....c..aP....f........
21:47:25.701881 ARP, Request who-has 192.168.1.142 tell 192.168.1.104, length 28
........P{.......h..........
21:47:25.703883 ARP, Reply 192.168.1.142 is-at 84:f3:eb:70:15:ce, length 46
...........p......P{.......h..................
21:47:30.822336 IP 192.168.1.104.38780 > 192.168.1.142.80: Flags [.], ack 1, win 29200, length 0
E..(.%@.@..c...h.....|.Pc..`....P.r..a..
21:47:30.823781 IP 192.168.1.142.80 > 192.168.1.104.38780: Flags [.], ack 322, win 5519, length 0
E..(...............h.P.|....c..aP....f........
21:47:41.061848 IP 192.168.1.104.38780 > 192.168.1.142.80: Flags [.], ack 1, win 29200, length 0
E..(.&@.@..b...h.....|.Pc..`....P.r..a..
21:47:41.064841 IP 192.168.1.142.80 > 192.168.1.104.38780: Flags [R.], seq 2, ack 321, win 5840, length 0
E..(...............h.P.|....c..`P....!........