My 129-f petition was touched on Monday & Tuesday. But my I130 is still untouched. A bit worried here. What could be the possible reasons? THanks.

We know that the USCIS are being very sporadic with their system updating. Some people are long ago approved and have no approval emails but have touches (including me), some don't even show a touch and have received their NOA2s, some have only seen an update on one petition yet received NOA2s for both. I think it would be unwise to 100% believe what CRIS is showing you at this time. The scanning of barcodes is not being properly actioned (and it could be that the person working on your case is only scanning one of your petitions when they are working on both of them).

I don't think "missing" touches on the I130 is going to be an issue. I think even if they have been separated that the I129F will get approved shortly and the I130 approved later. That will not delay your I129F from continuing on it's journey though and USCIS would be keeping your I130 at the records centre anyway

Have you tried the RFE trick to see if someone actually has your I130 assigned to them?