Hi Luca,
Which product bundle plugin are you using?
I have created the following test site for you:
https://wptestbox.com/luca/wp-admin/
User: admin
Pass: GEj!Sv!XE045LqmrG4
Will you please help us by reproducing the issue on the test site?
Thank You
Product Bundle compatibility
Luca Capula
Does it works with Product Bundles that have a variation product inside?