dns ip changed

Depends.

If your old IP still resolves and new one resolves as well, there should be no traffic loss at all. All DNS servers on the way will either have old or new IP already and will either send visitor to new or old location (from what I understand is the same server) so you should be good.

If only new IP is functioning, there will be outage for the time all the changes propagate through DNS. Let's say it works very quickly for the most part and can take some time 12-24 hours for some locations. It also depends on TTL and when the cache is cleared and new data retrieved.

Changing DNS IP has no negative impact on SEO if the website is up and running.

Due to these factors out of our control, however, you should allow up to 48 hours for any DNS changes to fully propagate across the Internet. If it's been more than 48 hours and your changes aren't reflecting correctly, there may be a different cause of the issue, such as incorrect DNS settings.