Hi,
I’m not sure how automation reacts on it’s own update step, but it will certainly reacts on update by script. If it works as multiplier, you are at risk to run chain reaction, which starts hundreds of new automation runs, mostly in a kind of pending state, which then ‘resolve’ for quite a long time.
So, test it well before turning ON. I can’t suggest solution without details, but when I encounter such kind of problem, I usually changed kind of trigger and it’s parameters. ‘When record matches condition’ usually fits better for me. If your condition is very complex and Automation editor is not flexible enough, you can use a formula.
Thanks for your answer @Alexey_Gusev
Eventually I was able to solve my problem adding another last modification by field that watches the field in the automation. Than in the automation I perform the action as conditional action only if the last modification by is not Automations.