For the first four hours of the voting period, poll watchdogs Kontra Daya and Vote Report PH already received verified reports of technical issues with the automated counting machine (ACM) and other election-related problems.

Vote Report PH has received reports around Metro Manila that some have been assigned to inaccessible election precincts, such as the second floor of the building.

The group also received reports of technical issues with ACMs, causing delays at the various precincts.

Further, some voters have also complained that despite carefully shading within the circle and the right number of allowable candidates, the over sensitivity of machines have mistakenly tagged some ballots as overvoting, nullifying votes on the ballot.

Kontra Daya Convenor Prof. Danilo Arao called on the Commission on Elections to "immediately come up with a resolution for these incidents because this clearly disenfranchises votes."

"It’s unfair for voters who made the effort to go to their precincts early only for their votes to be nullified,” Arao said.

Kontra Daya and Vote Report PH opened a vote monitoring center to allow voters to report election irregularities nationwide, including ACM errors, vote-buying, and harassment.