If Czech is pronounced 'check', then why isn't czar pronounced "char"?

There is discussion about the pronunciation of 'Czech' on this Wikipedia page, https://en.wikipedia.org/wiki/Name_of_the_Czech_Republic:-

"The Czech Republic's official formal and short names at the United Nations are ?eská republika and ?esko in Czech, and the Czech Republic and Czechia in English.[1] All these names derive from the name of the Czechs, the West Slavic ethnic group native to the Czech lands. Czechia (/?t??ki?/), the official English short name specified by the Czech government, is used by many international organisations and attested as early as 1841. However, most English speakers use [the] Czech Republic in all contexts.[2][3] Other languages generally have greater official use of a short form analogous to ?esko or Czechia[4][5] (such as French [la] Tchéquie, or Russian ?????/Chekhiya, or Korean ???/Ches?kko or ??/Chekho) although forms equivalent to "Czech Republic" are not uncommon."

This Wikipedia page https://en.wikipedia.org/wiki/Tsar gives the Cyrillic spelling of 'tsar' or 'czar'.

"The title tsar (Cyrillic: ????) is derived from the Latin title for the Roman emperors, caesar."

The last sentence I've copied about 'Czech' gives the Russian spelling - '?????'. It starts with a different letter from '????'. As I learnt them at school, '?' sounds like 'ch' in 'cheese', and '?' sounds like 'ts' in 'spots'.

Oh dear - all the Cyrillic characters don't seem to show on this page. You should be able to see them on the Wikipedia pages.

Here is a link to a Cyrillic keyboard where you can see the two characters in eighth and ninth places in the middle of the bottom row. The eighth one has the 'ts' sound, and the ninth the 'ch' sound.

https://www.lexilogos.com/keyboard/russian.htm

I will add that while Czech is an official spelling, Czar is only one of various transliterations from the Russian alphabet, and if familiar with our crystal ball, will know it is also csar, tsar and tzar, all pronounced the same but so far there is no official agreed spelling.

This link also says that czar is the primary American spelling.

https://www.askdifference.com/czar-vs-tsar

On the Wikipedia page, the pronunciation ot 'tsar', 'czar', or 'tzar' spellings is given (transferring the phonetic alphabet to more usual spelling) as 'zar', 'sar', or 'tsar'. 'Tsar' is the closest to the Russian spelling and pronunciation. Interestingly, the title is not Russian in origin - the world's first tsar was Simeon I of Bulgaria (919), and the world's last was Simeon II of Bulgaria (1946). English is not consistent in transliteration - we spell the composer Tchaikovsky (one of the two French spellings), but the playright is Chekov. Native English speakers balk at 'ts' or 'ps' or 'pn' at the start of a word - which is why people say 'soon-ami' for what used to be a 'tidal wave'. (I don't have any problem, but I speak French which does pronounce 'pneu' as 'pnuh' not 'nuh'. No reason except laziness for not pronouncing these initial consonants.) Both Polish and Czech spell it 'car' (pronounced 'tsar'). https://cs.wikipedia.org/wiki/Car https://fr.wikipedia.org/wiki/Piotr_Ilitch_Tcha%C3%AFkovski and the English Wikipedia page linked above

I have found an attribution of the (very odd) spelling "czar" to one particular person: a 16th century Austrian baron. The quote below is, in turn, a quote from Webster's Word Histories (1989) and is included in one of the (many!) answers in a discussion on the topic. Link to the complete discussion below.

We owe our peculiar spelling of czar to an Austrian diplomatist, Siegmund, Freiherr (Baron) von Herberstein (1486-1566). ... Herberstein wrote in Latin, but his spelling of Russian tsar was influenced by his native German. The c in Herberstein's czar may have come from Polish, but his z was surely added as a pronunciation indicator-z in German, like c in Polish, is pronounced ts. The English word czar first appeared in a 1555 translation of Herberstein's work [Rerum moscovitarum commentarii, or Commentaries on Muscovite Matters].

https://english.stackexchange.com/questions/43509/czar-vs-tsar-origins-and-pronunciation

This was really interesting! I have often wondered myself, since there is no Russian letter that it transcribed as "cz" in English.