All of a sudden lumetri color stopped working. I have to manually select lumetri from the drop-down menu and then it'll add. but it's irritating for big projects having many clips on it. I'm attaching the screenshot here. thanks in advance.
If you go to the Color tab in PPro, as soon as you change one of the parameters (e.g. exposure), the Lumetri Color Effect is added automatically to the clip.
I sort of get your problem. Now, have you tried my solution?
Open up the the Color tab and, with the clip of your choice selected, start changing one of the parameters. Lumetri will be added automatically to the clip as an effect.
Once I have a base grade I often copy/paste the Lumetri effect from one clip to the next and then finetune parameters. You can even create an Effect Preset which you can then drag & drop to any clip.