In his blog (in Spanish), Javier López Acevedo analyses the compatibility between the EUPL and the more permissive Apache license.

Regarding the EUPL, nothing in Apache versions 1.1 and 2.0 prohibits relicensing a larger work under this license. In the case of version 1.1 there are certain requirements - such as the existence of certain prohibitions on the use of the "Apache" brand - but in no case are they considered restrictions added by the EUPL licensor. Specifically, they are inherited from the original Apache license.

These requirements therefore do not affect the essential freedoms of the F/OSS, and are in accordance and compatible with Article 5 of the EUPL.

For more information:
https://blog.onesaitplatform.com/2024/02/09/la-licencia-publica-de-la-union-europea-y-apache2/