We have been able to reproduce this issue. However due to the current high workload caused by other ongoing projects we haven't been able to apply a fix at this time. As soon as we have been able to allocate sufficient development we'll continue searching for a fix.
Unfortunately there hasn't been any progress on this issue.
We are not aware of any possible solutions to the issue with OnMarkerClick event right now and we'll have to further investigate this on a later date. As resolving this issue will most likely require non trivial and technically challenging changes to the WebOSMaps code we'll have to plan the development time accordingly.
We have determined that the version of the OpenLayers API which the TMS WebOSMaps is currently based on is no longer working as expected in combination with recent mobile browsers on both Android and iOS.
At this time we are investigating which changes will be required to migrate to the latest version of the OpenLayers API which should be fully compatible with recent mobile browser. Unfortunately the architecture of the new OpenLayers API has changed dramatically which means this will require a lot of non trivial and technically challenging changes to the WebOSMaps code.