We have two Upstream providers both with IPv4 and IPv6 (BGP) all is working well on devices on the lan and can reach the internet ok.

the issue is the mikrotik itself.

For example, I cannot get OS Updates. complains about not able to reach DNS.

I done some testing and i suspect the Wan IP address is being used from provider 1 and BGP is sending the route via provider 2
Provider 2 is not able to route the traffic as its coming from the IP of Wan 2 and not the IP of Lan interface.

If i do a trace route and select the source IP of the /24 announced to both networks, all works. soon as i don't set the IP then the traffic fails, unless i set a static route to force the traffic via provider 1.

If i remove the static route and try from a pc on the local lan, all works ok as that is from a IP that is announced via both providers.

am i missing something?

found the solution.

Setup a BGP inbound rule to set ;set pref-src to the IP of the router /24 prefix and now the router can see the internet ok.

This might sound silly, but do you have DNS servers set via the IP>DNS menu?

Yes, all is working ok now.

I adjusted the BGP filter to include set pref-src <IP-Address> of the IP that is being announced to both providers and now the router can connect to DNS and other services ok.

without set pref-src set, it was using a Provider 1 IP address to try and connect to a remote peer via provider 2 which will fail.

now its using the correct IP, all works fine.