Yes.
NodogSplash is effectively no longer maintained, depends upon iptables, clashes with PBR and FW4, and it is very unlikely that anyone is going to migrate it to nftables.
However, openNDS is fully, 100%, migrated to nftables. It has a higher priority than FW4 (it must do as it a dynamic, border network demarcation service, hence the letters NDS). It is aware of and cooperates with the static FW4 firewall.
Once the openNDS dynamic firewall has allowed client traffic in/out the flow is passed on to the FW4 "firewall" ruleset for ongoing processing.
But here the issue with PBR arises as it attempts to mark packets that are already marked by openNDS using the same mask.
This is easy to fix when using openNDS and is best done in the PBR config.
I would suggest you remove NoDogSplash and all iptables packages and kmods unless you need them for something else, then install openNDS. Once you have it working, we can do the fix for PBR. (The default mode of openNDS is a "click to continue" splash page, very similar to the NoDogSplash default).