Weird JRuby platform issue

Gemfile

gem 'rake'

platforms :ruby do 
  gem 'pg'
end

# JRuby specific gems
platforms :jruby do
  # A JDBC-based ActiveRecord adapter for Postgres
  gem "activerecord-jdbcpostgresql-adapter", "~> 72"
  
  gem "jruby-openssl", "~> 0.15"
end

notes.md

bundler: bundler 4.0.9

ruby: cruby 3.4.9 jruby: jruby-10.0.4.0

arch: macos 26.4

Steps

1. switch to cruby 3.4.9 rbenv local 3.4.9
2. bundle install
3. add platforms bundle lock --add-platform arm64-darwin x86_64-linux universal-java
4. PLATFORMS should look like

PLATFORMS
  aarch64-linux
  aarch64-linux-musl
  arm64-darwin
  ruby
  universal-java
  x86_64-darwin
  x86_64-linux
  x86_64-linux-musl

5. delete lock rm Gemfile.lock
6. switch to JRuby rbenv local jruby-10.0.4.0
7. add platforms bundle lock --add-platform arm64-darwin x86_64-linux universal-java
8. blows up

Fetching gem metadata from https://rubygems.org/........
Resolving dependencies...
Could not find gem 'activerecord-jdbcpostgresql-adapter (~> 72) jruby' with
platform 'universal-java' in rubygems repository https://rubygems.org/ or
installed locally.

The source contains the following gems matching
'activerecord-jdbcpostgresql-adapter (~> 72) jruby':
  * activerecord-jdbcpostgresql-adapter-72.0-java
  * activerecord-jdbcpostgresql-adapter-72.1-java