While editing a non-saved R Markdown document in RStudion with the "Chunk Output Inline" option selected the IDE was correctly generating outputs inline and everything looked. However, after I saved the file and gave it a name, the IDE stopped generating outputs inline. When looking for a possible bug online, I found a few mentions of this problem (can't post 2+ links because of new account) but no solution. I did found a topic mentioning that:
There's a BUG in the software where the files that are saved with "ó ã õ" characters are not displaying tibble objects and plotly objects
In order to test this, I created a very simple .Rmd file, copied it and gave each copy a different name, one with ASCII characters only ("test") and the other with a non-ASCII character ("testá"). I found that although plots seem to be shown inline without problems in both files, data.frames (tibbles, and so on) do not show in the "testá" (the one with non-ASCII characters in its name).
My hypothesis is that RStudio stops showing output inline when file has non-ASCII character in its name. Note that I only tested this with the "á" character. This is not expected, since the file name should not interfere in how inline output is shown.
Here is a link for the files
Here is the content of both files in case you want to test without downloading my files.
plot(cars) test <- data.frame(x = c(1,2), y = c("?", "a")) test
I am using RStudio 2022.12.0+353 "Elsbeth Geranium" Release
(7d165dcfc1b6d300eb247738db2c7076234f6ef0, 2022-12-03) for Windows
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) RStudio/2022.12.0+353 Chrome/102.0.5005.167 Electron/19.1.3 Safari/537.36
R version 4.0.5 (2021-03-31) Platform: x86_64-w64-mingw32/x64 (64-bit) Running under: Windows 10 x64 (build 19044) Matrix products: default locale:  LC_COLLATE=Portuguese_Brazil.1252 LC_CTYPE=Portuguese_Brazil.1252  LC_MONETARY=Portuguese_Brazil.1252 LC_NUMERIC=C  LC_TIME=Portuguese_Brazil.1252 attached base packages:  stats graphics grDevices utils datasets methods base other attached packages:  forcats_0.5.1 stringr_1.4.0 purrr_0.3.4 readr_2.1.2  tidyr_1.2.0 tibble_3.1.6 ggplot2_3.3.5 tidyverse_1.3.1  dplyr_1.0.8 loaded via a namespace (and not attached):  bslib_0.3.1 tidyselect_1.1.2 xfun_0.30 haven_2.5.0  colorspace_2.0-3 vctrs_0.4.1 generics_0.1.2 htmltools_0.5.2  yaml_2.3.5 utf8_1.2.2 rlang_1.0.2 jquerylib_0.1.4  pillar_1.7.0 glue_1.6.2 withr_2.5.0 DBI_1.1.2  dbplyr_2.1.1 modelr_0.1.8 readxl_1.4.0 lifecycle_1.0.1  munsell_0.5.0 gtable_0.3.0 cellranger_1.1.0 rvest_1.0.2  evaluate_0.15 knitr_1.38 tzdb_0.3.0 fastmap_1.1.0  fansi_1.0.3 highr_0.9 broom_0.8.0 scales_1.2.0  backports_1.4.1 jsonlite_1.8.0 fs_1.5.2 hms_1.1.1  digest_0.6.29 stringi_1.7.6 grid_4.0.5 cli_3.2.0  tools_4.0.5 sass_0.4.1 magrittr_2.0.3 crayon_1.5.1  pkgconfig_2.0.3 ellipsis_0.3.2 xml2_1.3.3 reprex_2.0.1  lubridate_1.8.0 assertthat_0.2.1 rmarkdown_2.14 httr_1.4.2  rstudioapi_0.13 R6_2.5.1 compiler_4.0.5