RSelenium: Select option from dropdown - r

Question

I use RSelenium to fill in a webform. To select an option from a dropdown I use the following:
xpathoption <- paste0("//select[#id = '",samplepatient[p,'name'],"']/option[",samplepatient[p,'value'],"]")
optionelem <- remDrv$findElement(using = "xpath", xpathoption)
selectelem <- remDrv$findElement(using = "xpath"
, paste0("//select[#id = '",samplepatient[p,'name'],"']"))
optionelem$clickElement()
selectelem$screenshot(display = T)
I use the following to check if the correct option was selected:
remDrv$findElement(using = "xpath", paste0("//select[#id = '",samplepatient[p,'name'],"']"))$getElementAttribute("value")[[1]]
The problem I have is when the clickElement() command is run twice, the result of the last command changes. I also checked the outcome with screenshot(). It also shows that a different option is switched to when using the clickElement() command twice.
Is there a different way to select the option from a dropdown list, that is not creating this behavior?
I use a docker on ubuntu with firefox 3.0.1.
The form is from a calculator I want to use. To open the form itself you need to first check the disclaimer, like so:
remDrv$navigate('http://riskcalculator.facs.org/RiskCalculator/')
remDrv$findElement(using = "xpath", "//input[#id = 'chkDisclaimer']")$clickElement()
Sys.sleep(1)
remDrv$findElement(using = "xpath", "//input[#id = 'btnContinue']")$clickElement()
Sys.sleep(1)
a reproducable example after the disclaimer is:
#select age group
optionelem <- remDrv$findElement(using = "xpath", "//select[#id = 'AgeGroup']/option[3]")
selectelem <- remDrv$findElement(using = "xpath", "//select[#id = 'AgeGroup']")
#first attempt
optionelem$clickElement()
selectelem$getElementAttribute("value")
# result = 3
#second attempt
optionelem$clickElement()
selectelem$getElementAttribute("value")
# result = 1

Answer 1

As mentioned in one of the comments, the issue has not to do with RSelenium but with the docker used. I now use a chrome docker (standalone-chrome) that does not have the same issue with selecting an option in a dropdown.

Answer 2

I don't come across any issues when selecting options using clickElement
for example:
remDrv$navigate('http://riskcalculator.facs.org/RiskCalculator/')
remDrv$findElement("id", "chkDisclaimer")$clickElement()
Sys.sleep(1)
remDrv$findElement("id", "btnContinue")$clickElement()
Sys.sleep(1)
#select age group
ageElems <- remDrv$findElements("css", "#AgeGroup option")
ageElems[[3]]$clickElement()
#select Diabetes
diaElems <- remDrv$findElements("css", "#Diabetes option")
diaElems[[2]]$clickElement()
# Select Gender
genderElems <- remDrv$findElements("css", "#Gender option")
genderElems[[1]]$clickElement()
When running in Docker you can use "debug" image and a VNC viewer to see exactly whats happening in the browser.