This is similar to the closed topic: Frame ticks for a Log Log plot [closed]. Let me reuse (rm -rf)'s example here.
FrameTicks given through Show does not appear if used with LogLogPlot:
Show[
LogLogPlot[x^2 + x^3, {x, 1, 100}, Frame -> True],
FrameTicks -> {{All, None}, {{10, 30, 75}, None}}
]
This works though:
Show[
LogLogPlot[x^2 + x^3, {x, 1, 100}, Frame -> True],
FrameTicks -> {{All, None}, {{N@Log@#, #}& /@ {10, 30, 75}, None}}
]
Is this a bug or an expected behaviour?