Below is the working route/gateway table. Firewall rules used to push traffic to VPN
Internet:
Destination        Gateway            Flags     Netif Expire
default            192.168.0.1        UGS         em0
1.1.1.1            10.156.0.29        UGHS     ovpnc3
9.9.9.9            10.156.0.29        UGHS     ovpnc3
10.156.0.29        link#9             UH       ovpnc3
10.156.0.30        link#9             UHS         lo0
46.182.19.48       192.168.0.1        UGHS        em0
81.3.27.54         192.168.0.1        UGHS        em0
91.xx.xx.xx        10.156.0.29        UGHS     ovpnc3
127.0.0.1          link#6             UH          lo0
192.168.0.0/24     link#1             U           em0
192.168.0.234      link#1             UHS         lo0
192.168.20.0/24    link#2             U           em1
192.168.20.5       link#2             UHS         lo0
192.168.21.0/24    link#4             U           em3
192.168.21.5       link#4             UHS         lo0
Table from where is does not work.
Internet:
Destination        Gateway            Flags     Netif Expire
default            192.168.0.1        UGS         em0
1.0.0.1            10.149.0.13        UGHS     ovpnc1
1.1.1.1            10.156.0.29        UGHS     ovpnc3
9.9.9.9            10.156.0.29        UGHS     ovpnc3
9.9.9.10           10.149.0.13        UGHS     ovpnc1
10.149.0.13        link#10            UH       ovpnc1
10.149.0.14        link#10            UHS         lo0
10.156.0.29        link#9             UH       ovpnc3
10.156.0.30        link#9             UHS         lo0
46.182.19.48       192.168.0.1        UGHS        em0
81.3.27.54         192.168.0.1        UGHS        em0
85.xx.xx.xx        10.149.0.13        UGHS     ovpnc1
91.xx.xx.xx        10.156.0.29        UGHS     ovpnc3
127.0.0.1          link#6             UH          lo0
192.168.0.0/24     link#1             U           em0
192.168.0.234      link#1             UHS         lo0
192.168.20.0/24    link#2             U           em1
192.168.20.5       link#2             UHS         lo0
192.168.21.0/24    link#4             U           em3
192.168.21.5       link#4             UHS         lo0
This is the traceroute (which works) from when both VPNs are up.
traceroute to mintlinux.mirror.wearetriple.com (93.187.10.106), 30 hops max, 60 byte packets
 1  10.156.0.1 (10.156.0.1)  30.850 ms *  30.785 ms
 2  * v741.ce01.ams-01.nl.leaseweb.net (37.48.118.60)  30.738 ms *
 3  * ae-5.cr01.ams-01.nl.leaseweb.net (81.17.33.128)  30.667 ms *
 4  be-111.bb03.ams-01.leaseweb.net (31.31.38.200)  30.622 ms * be-112.bb03.ams-01.leaseweb.net (31.31.38.204)  30.578 ms
 5  * triple-it.telecity2.nl-ix.net (193.239.116.57)  37.565 ms *
 6  mirror.wearetriple.com (93.187.10.106)  37.501 ms  25.516 ms *
however, this is the error from the linux package manager and as i say, on the whole http browsing works.
Failed to fetch http://mintlinux.mirror.wearetriple.com/packages/dists/tessa/InRelease  Cannot initiate the connection to mintlinux.mirror.wearetriple.com:80 (2a00:1f00:dc06:10::106). - connect (101: Network is unreachable) Could not connect to mintlinux.mirror.wearetriple.com:80 (93.187.10.106), connection timed
you can see it is resolving in the application error message, so i don't think it is a dns issue. If i shutdown either of the VPN clients, this will work.