That is not reproducible in my R2022a. When "writetable" only has a first argument, it creates a text file with the same name as the input table.
Would you mind following the guidance below to restore your MATLAB settings to default?
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It seems that the problem you are experiencing is an abnormal operation of the product. Please apply the following instructions to initialize path and preference settings for the normal operation of MATLAB. If the following methods do not solve the problem, the only solution to the abnormal operation of the product is re-installation.
Right-click on the MATLAB execution icon to run MATLAB in administrator mode, and then execute the following commands in the MATLAB command window.
>> restoredefaultpath
>> rehash toolboxreset
>> rehash toolboxcache
>> sl_refresh_customizations % Please run this line only when you use Simulink related products.
>> savepath
>> prefdir
If there is no problem executing each command (a warning message is ok),
Open the directory along the path that appears when the last command is executed. Then close MATLAB.
Go up to the parent folder of the open directory, rename R20XXx to R20XXx_old (Ex. R2020a -> R2020a_old). Then launch MATLAB.
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