Based on the eIDAS amendment, the Trusted List format will also change. Any partner who has implemented a signature validation based on a Trusted List must note that the new format of version v6 is not backwards compatible. The new format is expected to be voted on in summer and will come into force 20 days later when it is published overnight. The validators will then have to be converted from that day onwards.
https://ec.europa.eu/digital-building-blocks/sites/display/DIGITAL/TLv6+is+coming%3A+Upgrade+now+to+avoid+signature+validation+failures
In the industry, it is generally to be expected that there will be difficulties during the changeover, even with the official validators.