I use Sonar Professional. Have not used my small/old M-Audio Oxygen 8 keyboard in a while. Probably not since upgrading to Windows 10 and likely a few Sonar updates. Experiencing some proverbial latency issue with it, so of course not good for precise timing in record. What might be some troubleshooting for this ( I kind of forgot the buffer formula on this stuff). Thanks

It is either audio interface buffer settings, plug-in delay compensation or both. Review the driver mode and audio interface buffer settings. If bypassing effects using the FX button in the Mix Module (keyboard shortcut E)  eliminates the problem, it is one or more plug-ins. While reading about the FX button also check out the PDC button (Live Input PDC Override).
 

Ok, yeah the bypass FX did in fact identify that as the problem. So assume now just process of elimination of each FX ( I'm not using many), or is there some other way to identify it?

Linear phase plug-ins (many have non-LP settings which may be more appropriate anyway), some dynamics processors, IR reverbs, IOW plug-ins not intended to be used while tracking.