We had one user who reached out to us about this issue and we have been able to reproduce the same in version 4.6.3.
For DTM GSD, you cannot enter 5 as a multiplier (default is always minimum 5 times GSD). The value you can enter as a multiplier now seems to be 5 times the GSD value as the minimum. For example, the GSD is 6.3 cm/pixel here and the minimum value you can enter as the multiplier is 31 (which is 5*6.28) instead of 5. The GSD value generated in the end is correct. You can verify that in QGIS or by looking at the tfw file. However, users will not be able to enter small multiplier values and will always need to use custom resolution.
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