Unfortunately, your wildcards won't work anymore. It's exactly as mentioned by Toshiya, the behaviour changed from 7.11.0 onwards.
Here's the response I got on my ticket (#64725) from Mendix support:
Hi Dennis, We fixed the following issue reported in the 59346: "Escaping wildcards is too difficult for the user." by making the escaping automatic. Unfortunately you are correct, the side-effect has been that wildcards no longer function as you were using them in 7.6.0. I discussed this at length with our R&D department as one could argue we broke existing functionality by processing the request made in ticket 59346. However R&D makes some valid counterpoints: We never documented the usage of wildcards. See https://docs.mendix.com/refguide/string-function-calls#contains. On the forum it's even mentioned that wildcards are not supported. See https://forum.mendix.com/link/questions/2503. We support isMatch in String function calls (https://docs.mendix.com/refguide/string-function-calls#ismatch). However, in XPath2 Match function has been added to support regular expressions. In short, we need to add a new XPath expression to support matching with wildcards/regular expressions and it is a feature request. Note: OQL can be suggested as an alternative to do wildcard searches. So you could use the isMatch function on the list after retrieving it in a microflow or use an OQL retrieve instead, as it supports wildcards, but this has to be done in Java. E.g. --> https://apidocs.mendix.com/7/runtime/com/mendix/core/Core.html#retrieveOQLDataTable-com.mendix.systemwideinterfaces.core.IContext-java.lang.String- But for support in XPaths (so you can do it again in a retrieve activity in a microflow directly) we will need to create a new feature. I will push for the responsible R&D team to add this to their (product) roadmap. However our product management receives requests for new features or feature improvements through many channels, our support portal being one of them. At Mendix we aim to build features that fit into the overall strategy and vision of the product and fulfill the requirements of a large group of our customers. This means that most feature requests, when chosen for implementation, will not be implemented exactly as it was requested in a feature request. Unfortunately this also means that we cannot provide detailed feedback for every individual feature request. Therefore we will close your ticket after having read and registered your suggestion. This does not mean we will not implement your idea, it means that our product management has registered your feature request, and will decide at a later stage if it will be included in the product roadmap. To clearly communicate what has been implemented, we choose to do this in one centralized location: the release notes provided at each new release. We would like to invite you to an important channel for providing feature requests to Mendix, the Mendix Idea forum. Every quarter all our customers can bring in feature requests, which can be enriched and voted on by others. Based on this feedback we determine which features have most value according to our customers and will be implemented. The Mendix Idea forum can be found at https://forum.mendix.com/link/ideas/ As always, we are grateful for your feedback and thank you for your understanding and patience. Kind regards, Jaap
TLDR; It needs to be submitted as Idea/new feature for any version higher than 7.10.0.