One of the common mistakes and misconceptions during Performing Umrah is to believe that touching the part of Kaaba or wiping over any part of it and Maqam-e-eIbrahim can bring Khair and Barakah. It has no basis in Sunnah or Hadith. The Holy Prophet PBUH never touched any part of Kaaba except Hajr-e-Aswad, the black stone or the Rukn-e-Yemeni, the Yemeni corner.
Innovations are forbidden in Islam, including during Umrah, hence it should be avoided. As far as touching Kaaba during Umrah, yes, you can touch it but it is not sunnah and it does not bring any special blessing. No hadith or Ayat of the Quran confirms it. However, with the Covid-19 pandemic, the Saudi authorities brought new regulations that didn’t allow pilgrims to touch the Kaaba or go closer to the Kaaba. Here is an update regarding the matter:
The Saudi authorities have removed protective barriers that were placed around Kaaba during the Covid pandemic. Umrah pilgrims can now touch the Kaaba and also kiss the black stone or Hajr-e-Aswad at the easter corner of the Kaaba. There were barriers put up around the Kaaba in order to stop the spread of Covid-19. With the barriers now removed, you can now touch the Holy Kaaba, touch the Yemeni corner and kiss the Black stone.
However, again, you should keep in mind that touching the Kaaba is not a Sunnah. Also, a few people tend to tear apart a piece of Ghilaf-e-Kaaba and carry it with them. This is also not recommended as it can’t bring any Barakah. Prophet PBUH used to kiss the black stone only, and you should also focus on that rather than touching the Kaaba again and again. Better focus on your Tawaf. But, yes you can touch the Kaaba during Umrah.