The Hebrew letter Chet does indeed correspond to the Arabic letter ح which makes the hard H sound. Since most Hebrew speakers cannot pronounce it, the closest sound to them is KH (also represented by the letter Kuf, Arabic equivalent is خ), thus when they try to pronounce "Hamas", they end up saying "KHAMASSS". And no, Chet is not the only Hebrew letter affected by a sound change like this, but it's the relevant one because it's used in the Hebrew spelling of "Hamas".
What news from England and Germany? The k thing (pronouncing the H in Hamas with a harsh hissing sound common in both Hebrew and Arabic but completely absent in English and other western languages) has been around at least since Oct. 7, probably much longer before that. It's a dog whistle. At best, it's in the spirit of mocking their language.
Considering that country names are different in different languages, I don't see much of a problem with it.
If the last sentence made you go "?" Check the
Chinese language name for China
Japanese name for Japan
Indian language names for India
But also what China, Japan and India have names for other countries and even alternate names for historical personalities in their languages. In some cases, even regional languages will have other alternate names.